Rant about IDE 2.X proxy issues on Windows (but also on Linux and MacOS)

nxfltn · September 18, 2025, 2:30am

Company requires a proxy with no password authentication for connection.
Arduino IDE 2.X won't start. I configured the proxy on the arduino-cli.yaml and it made no difference.

Set the proxy on powershell and tried launching from the powershell and still nothing.

IDE 1.X works fine.

I had the same issues on my Linux and MacOS machines with IDE 2.X and both took a long time to find a workaround, with the official suggestions of configuring proxy directly on Arduino files simply not working.

1.X has no issues transparently connecting through the proxy already set in the system. Why can't 2.X just do the same?

ptillisch · September 18, 2025, 3:24am

Hi @nxfltn. I'm going to ask you to provide some additional information that might help us to identify the problem.

This procedure is not intended to solve the problem. The purpose is to gather more information.

Please do this:

Close all Arduino IDE windows if the IDE is already running.
Start Windows "File Explorer".
Open the Arduino IDE installation folder.
ⓘ The default installation location is at one of the following paths:
- ```
C:\Program Files\Arduino IDE
```
- ```
C:\Users\<username>\AppData\Local\Programs\Arduino IDE
```
  (where <username> is your Windows username)
  If looking for it with your file manager or command line, note that the AppData folder is hidden by default. On Windows "File Explorer", you can make it visible by opening the "View" menu, then checking the box next to "☐ Hidden items".
In the folder listing of the Arduino IDE installation folder, hold the Shift key while clicking the right hand button on the mouse.
A context menu will open
Select "Open PowerShell window here" from the menu.
Windows PowerShell will now open with the current directory set to the Arduino IDE installation folder.
Type the following command in the PowerShell window:
```
& ".\Arduino IDE"
```
Press the Enter key.
Debug output should now be printed to the PowerShell window as Arduino IDE starts.
Wait until you are sure the IDE startup has gone into the hang state
(as indicated by no additional output being printed to the terminal).
Switch back to the PowerShell window if the Arduino IDE window took the focus.
Press the Ctrl+Shift+A keyboard shortcut.
This will select all the text in the PowerShell window.
Press the Ctrl+C keyboard shortcut.
This will copy the contents of the PowerShell window to the clipboard.
Open a reply here on this forum topic by clicking the "Reply" button.
Click the <CODE/> icon on the post composer toolbar.
This will add the forum's code block markup (```) to your reply to make sure the error messages are correctly formatted.

Code block icon on toolbar390×118 4.25 KB
Press the Ctrl+V keyboard shortcut.
This will paste the output into the code block.
Move the cursor outside of the code block markup before you add any additional text to your reply.
Click the "Reply" button to publish the post.

Please let us know if you have any questions or problems while following those instructions.

The Arduino IDE developers are tracking the task of adding an automatic proxy settings detection feature like Arduino IDE 1.x has here:

github.com/arduino/arduino-ide

Provide proxy settings auto-detection option

opened 08:51PM - 24 Feb 21 UTC

per1234

type: enhancement topic: code criticality: medium

### Describe the request Add an automatic proxy detection capability. Use auto…matic proxy detection by default. In addition to fully automatic and fully manual, the user should also have the option to enter an "**Automatic proxy configuration URL**": ![image](https://user-images.githubusercontent.com/8572152/193090932-63d63f44-b77f-4e53-a977-6b825d57c362.png) 🙂 No special configuration will be required for many users who connect to the Internet via a proxy. 🙂 Arduino IDE will be able to download the essential assets from the Internet on the first run after a fresh installation. ### Describe the current behavior Arduino IDE 2.x currently only supports manual proxy configuration, defaulting to not using a proxy: ![ide2](https://user-images.githubusercontent.com/8572152/109063589-2f92eb00-769e-11eb-970e-a5e4df50f4a8.png) On the first run after a fresh installation, the IDE must download some essential assets from the Internet. This will fail for users who connect to the Internet via a proxy. At the moment, dependencies on an Internet connection is not clearly communicated to the user (https://github.com/arduino/arduino-ide/issues/784, https://github.com/arduino/arduino-ide/issues/786, [`forum#1036875`](https://forum.arduino.cc/t/arduino-ide-2-00-and-lilygo-t-display-esp-s3-black-screen/1036875)), and may even cause the IDE to fail to start entirely (https://github.com/arduino/arduino-ide/issues/1438). Even though this can be mitigated by making the IDE handle such errors gracefully and by communicating about the problem, the lack of access to the assets will always be a less than ideal first experience. 🙁 Users who connect to the Internet via a proxy find the Arduino IDE is non-functional on the first run. 🙁 Users are forced to make fairly complex adjustments to the IDE's network configuration settings in order to use it at all. Users who have only used applications that automatically determine the correct configuration may not know how to find the correct values for these settings. 🙁 Users whose proxy uses [a "proxy auto-configuration" (PAC) file](https://developer.mozilla.org/en-US/docs/Web/HTTP/Proxy_servers_and_tunneling/Proxy_Auto-Configuration_PAC_file) will not be able to obtain the values required for manual configuration, meaning the IDE is permanently unusable. In many cases, it is possible to obtain the necessary proxy configuration from the operating system, as is done by Arduino IDE 1.x (and other applications): ![ide](https://user-images.githubusercontent.com/8572152/109063587-2efa5480-769e-11eb-880b-5c5ff4d13ef7.png) So this poor user experience is avoidable by technical means. ### Arduino IDE version 2.0.1-snapshot-96cf09d ### Operating system Windows ### Operating system version 10 ### Additional context #### Additional requests - https://forum.arduino.cc/t/arduino-2-x-proxy-system-settings/1169532 - https://forum.arduino.cc/t/rant-about-ide-2-x-proxy-issues-on-windows-but-also-on-linux-and-macos/1406669 #### Related - https://github.com/arduino/arduino-cli/pull/672 - https://forum.arduino.cc/t/arduino-ide-2-00-and-lilygo-t-display-esp-s3-black-screen/1036875 - https://github.com/arduino/arduino-ide/issues/1438 - https://github.com/arduino/arduino-cli/issues/1677 - https://forum.arduino.cc/t/arduino-2-0-wont-start/1038193 - https://forum.arduino.cc/t/arduino-2-0-will-not-start-past-the-loading-screen/1049023/9 - https://forum.arduino.cc/t/2-0-0-not-loading-windows-10/1035264

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Please only comment on the GitHub issue thread if you have new technical information that will assist with the resolution. General discussion and support requests are always welcome here on Arduino Forum.

nxfltn · September 18, 2025, 6:05am

Sorry for the critical post with no suggestion for improvement and thank you for the quick reply.

Here is the output from the prompt (proxy address changed for privacy, but I confirmed it's the correct address, as it is configured in this same machine I am using to reply now and on the other machines and other softwares):

Windows PowerShell
Copyright (C) Microsoft Corporation. All rights reserved.

Install the latest PowerShell for new features and improvements! https://aka.ms/PSWindows

Loading personal and system profiles took 1064ms.
(base) PS C:\Users\aghen> cd C:\Users\aghen\AppData\Local\Programs\Arduino IDE
Set-Location : A positional parameter cannot be found that accepts argument 'IDE'.
At line:1 char:1
+ cd C:\Users\aghen\AppData\Local\Programs\Arduino IDE
+ ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
    + CategoryInfo          : InvalidArgument: (:) [Set-Location], ParameterBindingException
    + FullyQualifiedErrorId : PositionalParameterNotFound,Microsoft.PowerShell.Commands.SetLocationCommand

(base) PS C:\Users\aghen> cd "C:\Users\aghen\AppData\Local\Programs\Arduino IDE"
(base) PS C:\Users\aghen\AppData\Local\Programs\Arduino IDE> & ".\Arduino IDE"
(base) PS C:\Users\aghen\AppData\Local\Programs\Arduino IDE>
Arduino IDE 2.3.6
Checking for frontend application configuration customizations. Module path: C:\Users\aghen\AppData\Local\Programs\Arduino IDE\resources\app\lib\backend\electron-main.js, destination 'package.json': C:\Users\aghen\AppData\Local\Programs\Arduino IDE\resources\app\package.json
Setting 'theia.frontend.config.appVersion' application configuration value to: "2.3.6" (type of string)
Setting 'theia.frontend.config.cliVersion' application configuration value to: "1.2.0" (type of string)
Setting 'theia.frontend.config.buildDate' application configuration value to: "2025-04-09T11:26:55.498Z" (type of string)
Frontend application configuration after modifications: {"applicationName":"Arduino IDE","defaultTheme":{"light":"arduino-theme","dark":"arduino-theme-dark"},"defaultIconTheme":"none","electron":{"windowOptions":{},"showWindowEarly":true,"splashScreenOptions":{},"uriScheme":"arduino-ide"},"defaultLocale":"","validatePreferencesSchema":false,"reloadOnReconnect":true,"uriScheme":"theia","preferences":{"window.title":"${rootName}${activeEditorShort}${appName}","files.autoSave":"afterDelay","editor.minimap.enabled":false,"editor.tabSize":2,"editor.scrollBeyondLastLine":false,"editor.quickSuggestions":{"other":false,"comments":false,"strings":false},"editor.maxTokenizationLineLength":500,"editor.bracketPairColorization.enabled":false,"breadcrumbs.enabled":false,"workbench.tree.renderIndentGuides":"none","explorer.compactFolders":false},"appVersion":"2.3.6","cliVersion":"1.2.0","buildDate":"2025-04-09T11:26:55.498Z"}
Starting backend process. PID: 20708
Showing main window early
Using browser-only version of superagent in non-browser environment
Configuration directory URI: 'file:///c%3A/Users/aghen/.arduinoIDE'
Configuring to accept webviews on '^.+\.webview\..+$' hostname.
2025-09-18T05:53:04.086Z root INFO Backend u.initialize: 23.7 ms [Finished 0.561 s after backend start]
2025-09-18T05:53:04.087Z root INFO Backend Object.initialize: 21.5 ms [Finished 0.561 s after backend start]
2025-09-18T05:53:04.087Z root INFO Backend a.initialize: 1.4 ms [Finished 0.561 s after backend start]
2025-09-18T05:53:04.087Z root INFO Backend a.initialize: 1.2 ms [Finished 0.561 s after backend start]
2025-09-18T05:53:04.087Z root INFO Backend u.initialize: 1.5 ms [Finished 0.562 s after backend start]
2025-09-18T05:53:04.089Z root INFO Backend l.initialize: 22.5 ms [Finished 0.562 s after backend start]
2025-09-18T05:53:04.095Z root INFO configured all backend app contributions
2025-09-18T05:53:04.095Z root INFO Backend l.onStart: 1.0 ms [Finished 0.571 s after backend start]
2025-09-18T05:53:04.096Z root INFO Backend d.onStart: 0.1 ms [Finished 0.572 s after backend start]
2025-09-18T05:53:04.096Z root INFO Backend a.onStart: 0.3 ms [Finished 0.572 s after backend start]
2025-09-18T05:53:04.096Z config INFO >>> Initializing CLI configuration...
2025-09-18T05:53:04.096Z root INFO Backend x.onStart: 0.3 ms [Finished 0.572 s after backend start]
2025-09-18T05:53:04.096Z config INFO Loading CLI configuration from c:\Users\aghen\.arduinoIDE\arduino-cli.yaml...
2025-09-18T05:53:04.096Z daemon INFO Starting daemon from C:\Users\aghen\AppData\Local\Programs\Arduino IDE\resources\app\lib\backend\resources\arduino-cli.exe...
2025-09-18T05:53:04.096Z root INFO Backend w.onStart: 0.3 ms [Finished 0.573 s after backend start]
2025-09-18T05:53:04.096Z discovery-log INFO start
2025-09-18T05:53:04.096Z discovery-log INFO start new deferred
2025-09-18T05:53:04.096Z root INFO Backend v.onStart: 0.2 ms [Finished 0.573 s after backend start]
2025-09-18T05:53:04.096Z root INFO Backend a.onStart: 0.1 ms [Finished 0.573 s after backend start]
2025-09-18T05:53:04.101Z root INFO Theia app listening on http://127.0.0.1:52129.
2025-09-18T05:53:04.101Z root INFO Finished starting backend application: 4.7 ms [Finished 0.578 s after backend start]
2025-09-18T05:53:04.191Z root WARN The local plugin referenced by local-dir:/c%3A/Users/aghen/.arduinoIDE/plugins does not exist.
2025-09-18T05:53:04.191Z root WARN The local plugin referenced by local-dir:/c%3A/Users/aghen/.arduinoIDE/deployedPlugins does not exist.
2025-09-18T05:53:04.191Z root WARN The local plugin referenced by local-dir:C:\Users\aghen\.arduinoIDE\plugins does not exist.
2025-09-18T05:53:04.208Z config INFO Loaded CLI configuration: {"network":{"proxy":"http://proxy.aghen.com:8080"},"board_manager":{"additional_urls":[]}}
2025-09-18T05:53:04.208Z config INFO Loading fallback CLI configuration to get 'directories.data' and 'directories.user'
2025-09-18T05:53:04.248Z daemon INFO time="2025-09-18T14:53:04+09:00" level=info msg="arduino-cli version 1.2.0"
2025-09-18T05:53:04.250Z daemon INFO time="2025-09-18T14:53:04+09:00" level=info msg="Using config file: c:\\Users\\aghen\\.arduinoIDE\\arduino-cli.yaml"
2025-09-18T05:53:04.250Z daemon INFO time="2025-09-18T14:53:04+09:00" level=info msg="Executing `arduino-cli daemon`"
2025-09-18T05:53:04.261Z daemon INFO Daemon is now listening on 127.0.0.1:52130
{"IP":"127.0.0.1","Port":"52130"}
2025-09-18T05:53:04.261Z daemon INFO Daemon is running.
2025-09-18T05:53:04.263Z config INFO Loaded fallback CLI configuration: {"directories":{"user":"C:\\Users\\aghen\\Documents\\Arduino","data":"C:\\Users\\aghen\\AppData\\Local\\Arduino15"}}
2025-09-18T05:53:04.263Z config INFO Merged CLI configuration with the fallback: {"directories":{"user":"C:\\Users\\aghen\\Documents\\Arduino","data":"C:\\Users\\aghen\\AppData\\Local\\Arduino15"},"network":{"proxy":"http://proxy.aghen.com:8080"},"board_manager":{"additional_urls":[]}}
2025-09-18T05:53:04.263Z config INFO Loaded the CLI configuration.
2025-09-18T05:53:04.274Z config INFO Mapped the CLI configuration: {"dataDirUri":"file:///c%3A/Users/aghen/AppData/Local/Arduino15","sketchDirUri":"file:///c%3A/Users/aghen/Documents/Arduino","additionalUrls":[],"network":{"protocol":"http","hostname":"proxy.aghen.com","password":"","username":"","port":"8080"},"locale":"en"}
2025-09-18T05:53:04.274Z config INFO Validating the CLI configuration...
2025-09-18T05:53:04.277Z config INFO The CLI config is valid.
2025-09-18T05:53:04.277Z config INFO <<< Initialized the CLI configuration.
2025-09-18T05:53:04.297Z root INFO Resolve plugins list: 199.0 ms [Finished 0.774 s after backend start]
2025-09-18T05:53:04.312Z daemon INFO time="2025-09-18T14:53:04+09:00" level=info msg="Checking signature" index="C:\\Users\\aghen\\AppData\\Local\\Arduino15\\package_index.json" signatureFile="C:\\Users\\aghen\\AppData\\Local\\Arduino15\\package_index.json.sig" trusted=true
2025-09-18T05:53:04.313Z daemon INFO time="2025-09-18T14:53:04+09:00" level=info msg="Loading hardware from: C:\\Users\\aghen\\AppData\\Local\\Arduino15\\packages"
2025-09-18T05:53:04.313Z daemon INFO time="2025-09-18T14:53:04+09:00" level=info msg="Starting download" url="https://downloads.arduino.cc/monitor/serial-monitor/serial-monitor_v0.15.0_Windows_64bit.zip"
2025-09-18T05:53:05.247Z root INFO creating connection for 1
2025-09-18T05:53:06.019Z root WARN A command editor.action.toggleStickyScroll is already registered.
Opening channel for service path '/services/electron-window'.
Opening channel for service path '/services/ide-updater'.
2025-09-18T05:53:06.106Z root INFO Deploy plugins list: 2007.5 ms [Finished 2.582 s after backend start]
2025-09-18T05:53:06.140Z root INFO Start frontend contributions: 294.7 ms [Finished 1.990 s after frontend start]
2025-09-18T05:53:06.140Z root INFO Changed application state from 'init' to 'started_contributions'.
2025-09-18T05:53:06.147Z root INFO Changed application state from 'started_contributions' to 'attached_shell'.
2025-09-18T05:53:06.147Z root INFO >>> Restoring the layout state...
2025-09-18T05:53:06.202Z root INFO [7f9cee1d-f3f3-461c-b993-ec76ae5f1229] Waiting for backend deployment: 41.2 ms [Finished 2.028 s after frontend start]
2025-09-18T05:53:06.595Z root INFO [hosted-plugin: 9572] PLUGIN_HOST(9572) starting instance
[Object: null prototype] {}
2025-09-18T05:53:07.013Z root INFO [7f9cee1d-f3f3-461c-b993-ec76ae5f1229] Sync of 23 plugins: 846.8 ms [Finished 2.874 s after frontend start]
2025-09-18T05:53:34.338Z root ERROR Detected an error response during the gRPC core client initialization: code: 13, message: downloading builtin:serial-monitor@0.15.0 tool: Get "https://downloads.arduino.cc/monitor/serial-monitor/serial-monitor_v0.15.0_Windows_64bit.zip": dial tcp 104.18.11.21:443: i/o timeout
2025-09-18T05:53:34.338Z daemon INFO time="2025-09-18T14:53:34+09:00" level=info msg="Starting download" url="https://downloads.arduino.cc/tools/ctags-5.8-arduino11-pm-i686-mingw32.zip"
2025-09-18T05:54:04.340Z root ERROR Detected an error response during the gRPC core client initialization: code: 13, message: downloading builtin:ctags@5.8-arduino11 tool: Get "https://downloads.arduino.cc/tools/ctags-5.8-arduino11-pm-i686-mingw32.zip": dial tcp 104.18.11.21:443: i/o timeout
2025-09-18T05:54:04.340Z daemon INFO time="2025-09-18T14:54:04+09:00" level=info msg="Starting download" url="https://downloads.arduino.cc/discovery/dfu-discovery/dfu-discovery_v0.1.2_Windows_64bit.zip"
2025-09-18T05:54:34.340Z root ERROR Detected an error response during the gRPC core client initialization: code: 13, message: downloading builtin:dfu-discovery@0.1.2 tool: Get "https://downloads.arduino.cc/discovery/dfu-discovery/dfu-discovery_v0.1.2_Windows_64bit.zip": dial tcp 104.18.11.21:443: i/o timeout
2025-09-18T05:54:34.341Z daemon INFO time="2025-09-18T14:54:34+09:00" level=info msg="Starting download" url="https://downloads.arduino.cc/discovery/mdns-discovery/mdns-discovery_v1.0.9_Windows_64bit.zip"
2025-09-18T05:55:04.344Z root ERROR Detected an error response during the gRPC core client initialization: code: 13, message: downloading builtin:mdns-discovery@1.0.9 tool: Get "https://downloads.arduino.cc/discovery/mdns-discovery/mdns-discovery_v1.0.9_Windows_64bit.zip": dial tcp 104.18.10.21:443: i/o timeout
2025-09-18T05:55:04.345Z daemon INFO time="2025-09-18T14:55:04+09:00" level=info msg="Starting download" url="https://downloads.arduino.cc/discovery/serial-discovery/serial-discovery_v1.4.1_Windows_64bit.zip"

I will keep an eye on the github for the implementation of the proxy auto-configuration, although the issue now is that the IDE GUI won't launch if there is no internet connection, so even the manual proxy configuration settings can't be reached.

ptillisch · September 18, 2025, 6:32pm

OK, that makes the problem clear:

nxfltn:

2025-09-18T05:53:34.338Z root ERROR Detected an error response during the gRPC core client initialization: code: 13, message: downloading builtin:serial-monitor@0.15.0 tool: Get "https://downloads.arduino.cc/monitor/serial-monitor/serial-monitor_v0.15.0_Windows_64bit.zip": dial tcp 104.18.11.21:443: i/o timeout
2025-09-18T05:53:34.338Z daemon INFO time="2025-09-18T14:53:34+09:00" level=info msg="Starting download" url="https://downloads.arduino.cc/tools/ctags-5.8-arduino11-pm-i686-mingw32.zip"
2025-09-18T05:54:04.340Z root ERROR Detected an error response during the gRPC core client initialization: code: 13, message: downloading builtin:ctags@5.8-arduino11 tool: Get "https://downloads.arduino.cc/tools/ctags-5.8-arduino11-pm-i686-mingw32.zip": dial tcp 104.18.11.21:443: i/o timeout
2025-09-18T05:54:04.340Z daemon INFO time="2025-09-18T14:54:04+09:00" level=info msg="Starting download" url="https://downloads.arduino.cc/discovery/dfu-discovery/dfu-discovery_v0.1.2_Windows_64bit.zip"
2025-09-18T05:54:34.340Z root ERROR Detected an error response during the gRPC core client initialization: code: 13, message: downloading builtin:dfu-discovery@0.1.2 tool: Get "https://downloads.arduino.cc/discovery/dfu-discovery/dfu-discovery_v0.1.2_Windows_64bit.zip": dial tcp 104.18.11.21:443: i/o timeout
2025-09-18T05:54:34.341Z daemon INFO time="2025-09-18T14:54:34+09:00" level=info msg="Starting download" url="https://downloads.arduino.cc/discovery/mdns-discovery/mdns-discovery_v1.0.9_Windows_64bit.zip"
2025-09-18T05:55:04.344Z root ERROR Detected an error response during the gRPC core client initialization: code: 13, message: downloading builtin:mdns-discovery@1.0.9 tool: Get "https://downloads.arduino.cc/discovery/mdns-discovery/mdns-discovery_v1.0.9_Windows_64bit.zip": dial tcp 104.18.10.21:443: i/o timeout

Explanation

Unfortunately a bug was introduced in Arduino IDE 2.3.3 that causes the proxy configuration to be ignored for these specific downloads.

github.com/arduino/arduino-ide

Boards Manager doesn't use configured proxy

opened 09:41AM - 11 Sep 25 UTC

nivhg

type: imperfection topic: CLI

### Describe the problem The proxy settings configured in the Arduino IDE prefe…rences are not being used for certain operations. In our environment, proxy is mandatory for HTTPS connection. Our firewall replaces certificates with a false certificate when the proxy is not used. 🐛 Arduino IDE is not using the firewall for installations of boards platforms. This causes the installation to fail. ### To reproduce 1. Install Arduino IDE on a environment where proxy is mandatory. 1. Use Boards Manager to install any boards platform (e.g., "Arduino megaAVR Boards"). 🐛 The installation fails. ### Expected behavior Packages needed by the board are successfully downloaded. ### Arduino IDE version 2.3.7-nightly-20250911 ### Operating system Windows ### Operating system version 11 24H2 ### Additional context I have this proxy configuration in `%USERPROFILE%\.arduinoIDE\arduino-cli.yaml`: ```yaml network: proxy: http://172.21.178.254:3128/ user_agent_ext: daemon ``` The complete file: [`arduino-cli.yaml`](https://github.com/user-attachments/files/22271850/arduino-cli.yaml) --- I see certificate errors in the logs: ```text 2025-09-11 10:54:17 Checking for update 2025-09-11 10:54:17 Error: Error: net::ERR_CERT_AUTHORITY_INVALID at SimpleURLLoaderWrapper.<anonymous> (node:electron/js2c/browser_init:2:114352) at SimpleURLLoaderWrapper.emit (node:events:519:28) 2025-09-11 10:54:17 2025-09-11T08:54:17.703Z root INFO [hosted-plugin: 4656] PLUGIN_HOST(4656): PluginManagerExtImpl/loadPlugin(C:\Users\user\AppData\Local\Programs\arduino-ide\resources\app\plugins\vscode-builtin-json-language-features\extension\client\dist\node\jsonClientMain) 2025-09-11 10:54:17 2025-09-11T08:54:17.938Z root INFO [hosted-plugin: 4656] PLUGIN_HOST(4656): PluginManagerExtImpl/loadPlugin(C:\Users\user\AppData\Local\Programs\arduino-ide\resources\app\plugins\vscode-arduino-api\extension\dist\extension.js) 2025-09-11 10:54:17 2025-09-11T08:54:17.947Z root INFO [hosted-plugin: 4656] calling activation function on Arduino IDE API for VS Code extensions 2025-09-11 10:54:17 2025-09-11T08:54:17.983Z root INFO [43dd9994-0848-4fb6-b9cc-d97597fb5de0] Starting plugins. 2025-09-11 10:54:18 2025-09-11T08:54:18.340Z root INFO [hosted-plugin: 4656] PLUGIN_HOST(4656): PluginManagerExtImpl/loadPlugin(C:\Users\user\AppData\Local\Programs\arduino-ide\resources\app\plugins\cortex-debug\extension\dist\extension.js) 2025-09-11 10:54:18 2025-09-11T08:54:18.429Z root INFO [hosted-plugin: 4656] Debug configuration provider has been registered: cortex-debug, trigger: 1 2025-09-11 10:54:18 2025-09-11T08:54:18.430Z root INFO [hosted-plugin: 4656] calling activation function on Cortex-Debug 2025-09-11 10:54:18 2025-09-11T08:54:18.441Z root INFO [hosted-plugin: 4656] GDB server console created 2025-09-11 10:54:18 2025-09-11T08:54:18.478Z root INFO [43dd9994-0848-4fb6-b9cc-d97597fb5de0] Start of 23 plugins: 2196.2 ms [Finished 8.555 s after frontend start] 2025-09-11 10:54:18 2025-09-11T08:54:18.941Z root ERROR ---- !!!SLOW!!! DURATION: search took 1472.752 ms. Args: [{"type":"Updatable"}] ---- 2025-09-11 10:54:18 2025-09-11T08:54:18.942Z fwuploader ERROR Error: Process exited with exit code: 1 at ChildProcess.<anonymous> (C:\Users\user\AppData\Local\Programs\arduino-ide\resources\app\lib\backend\main.js:2:1104768) at ChildProcess.emit (node:events:519:28) at ChildProcess._handle.onexit (node:internal/child_process:294:12) 2025-09-11 10:54:18 2025-09-11T08:54:18.943Z fwuploader ERROR Error: Process exited with exit code: 1 at ChildProcess.<anonymous> (C:\Users\user\AppData\Local\Programs\arduino-ide\resources\app\lib\backend\main.js:2:1104768) at ChildProcess.emit (node:events:519:28) at ChildProcess._handle.onexit (node:internal/child_process:294:12) ``` Full logs: [`2025-09-11_log.log`](https://github.com/user-attachments/files/22271851/2025-09-11_log.log) --- When using Arduino IDE 2.1.0, Arduino IDE says that Arduino CLI is offline, but it does manage to install the boards platforms. #### Additional reports - https://forum.arduino.cc/t/rant-about-ide-2-x-proxy-issues-on-windows-but-also-on-linux-and-macos/1406669 #### Related - https://github.com/arduino/arduino-ide/issues/2232 ### Issue checklist - [x] I searched for previous reports in [the issue tracker](https://github.com/arduino/arduino-ide/issues?q=) - [x] I verified the problem still occurs when using the latest [nightly build](https://www.arduino.cc/en/software#nightly-builds) - [x] My report contains all necessary details

github.com/arduino/arduino-cli

`core install` command ignores `network.proxy` configuration

opened 07:08PM - 12 Apr 25 UTC

closed 09:00AM - 16 Apr 25 UTC

DVK251

conclusion: resolved topic: code type: imperfection topic: package-management

### Describe the problem Arduino CLI must access the Internet for various opera…tions. It can be configured to use a proxy server via the [`network.proxy` configuration key](https://arduino.github.io/arduino-cli/dev/configuration/#:~:text=the%20network%20connection.-,proxy,-%2D%20URL%20of%20the). 🐛 The `network.proxy` configuration key is ignored by the `core install` command. ### To reproduce #### Setup ```text $ git clone https://github.com/arduino/arduino-cli && cd arduino-cli [...] $ git checkout 6320f6eb # Checkout the last good commit. [...] $ task build [...] $ export ARDUINO_DIRECTORIES_DATA="/tmp/arduino-cli-directories/data" # Use a throwaway data folder for the demo. $ export ARDUINO_DIRECTORIES_DOWNLOADS="/tmp/arduino-cli-directories/downloads" $ rm -r "$ARDUINO_DIRECTORIES_DATA" "$ARDUINO_DIRECTORIES_DOWNLOADS" # Make sure there aren't existing files that would throw off the results. [...] $ ./arduino-cli lib update-index # This is required as a preparatory operation because `core install` unnecessarily triggers a libraries index update if it is not already updated. $ export ARDUINO_NETWORK_PROXY="http://foouser:foopass@httpstat.us/404:42/" # Configure Arduino CLI to use a proxy, intentionally using a non-functional configuration. ``` #### Demonstration of correct operation pre-regression ```text $ ./arduino-cli core install arduino:avr # Attempt to install a platform while using a proxy. Downloading packages... arduino:arduinoOTA@1.3.0 Get "https://downloads.arduino.cc/tools/arduinoOTA-1.3.0-windows_386.zip": Internal Server Error Error during install: Get "https://downloads.arduino.cc/tools/arduinoOTA-1.3.0-windows_386.zip": Internal Server Error ``` 🙂 The operation failed due to the non-functional proxy configuration, proving that the `core install` command does use the configured proxy for its downloads. #### Demonstration of incorrect operation post-regression ```text $ git checkout master [...] $ task build [...] $ ./arduino-cli core install arduino:avr $ ./arduino-cli core install arduino:avr Downloading packages... arduino:arduinoOTA@1.3.0 downloaded arduino:avr-gcc@7.3.0-atmel3.6.1-arduino7 downloaded arduino:avrdude@6.3.0-arduino17 downloaded arduino:avr@1.8.6 downloaded Installing arduino:arduinoOTA@1.3.0... Configuring tool.... arduino:arduinoOTA@1.3.0 installed Installing arduino:avr-gcc@7.3.0-atmel3.6.1-arduino7... Configuring tool.... arduino:avr-gcc@7.3.0-atmel3.6.1-arduino7 installed Installing arduino:avrdude@6.3.0-arduino17... Configuring tool.... arduino:avrdude@6.3.0-arduino17 installed Installing platform arduino:avr@1.8.6... Configuring platform.... Platform arduino:avr@1.8.6 installed ``` 🐛 The installation was successful even though Arduino CLI was configured to use a non-functional proxy. This proves that the `core install` command does not use the configured proxy for its downloads. #### Demonstration of correct operation of `lib install` command ```text $ export ARDUINO_DIRECTORIES_USER="/tmp/arduino-cli-directories/user" # Use a throwaway user folder for the demo. $ rm -r "$ARDUINO_DIRECTORIES_USER" # Make sure there aren't existing files that would throw off the results. [...] $ ./arduino-cli lib install Servo Downloading Servo@1.2.2... Servo@1.2.2 Get "https://downloads.arduino.cc/libraries/github.com/arduino-libraries/Servo-1.2.2.zip?query=install": Internal Server Error Error installing Servo: Can't download library: Get "https://downloads.arduino.cc/libraries/github.com/arduino-libraries/Servo-1.2.2.zip?query=install": Internal Server Error ``` 🙂 The operation failed due to the non-functional proxy configuration, proving that the `lib install` command does use the configured proxy for its downloads. ### Expected behavior All operations that access the Internet respect the `network.proxy` configuration. ### Arduino CLI version 23ed1b12f7263b29b2264ffa9944b8f804d57c6f ### Operating system Windows ### Operating system version - 10, build 1809 - 11 ### Additional context I bisected the regression to 1fddba76a15360b083f457c1028065f764747b10 / https://github.com/arduino/arduino-cli/pull/2565 (does not occur when using the build at the previous commit 6320f6eb). ### Issue checklist - [x] I searched for previous reports in [the issue tracker](https://github.com/arduino/arduino-cli/issues?q=) - [X] I verified the problem still occurs when using the [nightly build](https://arduino.github.io/arduino-cli/dev/installation/#nightly-builds) - [X] My report contains all necessary details

The bug is actually in the Arduino CLI helper tool that provides much of the non-GUI functionality for Arduino IDE under the hood. The bug has already been fixed in Arduino CLI, but Arduino IDE is still using the version of Arduino CLI that has the bug. So the bug will be fixed in Arduino IDE as soon as the developers update the version of Arduino CLI it uses.

Workaround

There are a couple of possible workarounds. I'll describe both of them and you can choose whichever one seems most convenient to you:

Use Older Version of Arduino IDE

One workaround would be to use the last version of Arduino IDE from before the regression: 2.3.2. This is the most simple approach, but is not ideal because some significant enhancements and fixes have been made since 2.3.2.

I'll provide instructions you can follow to install Arduino IDE 2.3.2:

Click the following link to open the page for the 2.3.2 release in the Arduino IDE GitHub repository:
Release 2.3.2 · arduino/arduino-ide · GitHub
From the list of download links under the "Assets" section of the page, click the link with the name:
- If you want the installer package: arduino-ide_2.3.2_Windows_64bit.exe
- If you want the "MSI" package: arduino-ide_2.3.2_Windows_64bit.msi
- If you want the "ZIP" package: arduino-ide_2.3.2_Windows_64bit.zip
ⓘ If you aren't sure which one you need, use arduino-ide_2.1.1_Windows_64bit.exe
Wait for the download to finish.
Install Arduino IDE from the downloaded file as you would normally do.

You will now find that Arduino IDE shows an "Update Available" dialog on startup, to offer you an update to the newer version of Arduino IDE. If you click the "SKIP VERSION" button in the "Update Available" dialog, it will cause Arduino IDE to no longer offer the update to 2.3.6, but it will appear once again after the next release (e.g., 2.3.7) comes out, which will hopefully have the bug fix.

Use Arduino CLI to Install Platforms

You can work around the bug by using the latest version of Arduino CLI (which has the bug fix) directly to install these files and any other boards platforms you need.

I'll provide instructions you can follow to do that:

Install Arduino CLI:
https://arduino.github.io/arduino-cli/latest/installation/
Start Windows "File Explorer".
Navigate to the Arduino CLI installation folder.
In the folder listing of the Arduino CLI installation folder, hold the Shift key while clicking the right hand button on the mouse.
A context menu will open
Select "Open PowerShell window here" from the menu.
Windows PowerShell will now open with the current directory set to the Arduino CLI installation folder.
If you need to install any 3rd party boards platforms that require an "Additional Boards Manager URL" to be provided (example), run a command with the following format to configure the URL:
```
.\arduino-cli --config-file "$Env:HOMEDRIVE$Env:HOMEPATH\.arduinoIDE\arduino-cli.yaml" config set board_manager.additional_urls <URL>
```
(where <URL> is the URL for the platform)
- For more information see:
  https://arduino.github.io/arduino-cli/latest/commands/arduino-cli_config_set/

Run the command (reference) with the following form:

.\arduino-cli  --config-file "$Env:HOMEDRIVE$Env:HOMEPATH\.arduinoIDE\arduino-cli.yaml" core list --all

Find the Arduino boards platforms (AKA "cores") you would like to install in the list. Take note of the machine identifier that is shown in the "ID" column.
ⓘ Alternatively, you can use the arduino-cli core search command to get the information about a specific platform.
Run a command (reference) with the following format to install the platforms:
```
.\arduino-cli  --config-file "$Env:HOMEDRIVE$Env:HOMEPATH\.arduinoIDE\arduino-cli.yaml" core install <ID>
```
(where <ID> is the machine identifier you saw in the arduino-cli core list command output)

After doing that, you should be able to start and use Arduino IDE. You should use Arduino CLI again whenever you need to install or update a platform.

Other Proxy Handling Bugs

IDE Updates

Note that there is a separate bug that causes Arduino IDE to not use the proxy for updates:

github.com/arduino/arduino-ide

IDE updater doesn't use the configured proxy

opened 12:41PM - 20 Sep 23 UTC

wh201906

topic: code type: imperfection

### Describe the problem Arduino IDE makes various uses of resources accessed v…ia the Internet. Some users can only access the Internet via a proxy server. Arduino IDE can be configured to use the proxy server via the "**Network**" tab of the "**Preferences**" dialog. 🐛 When updating the IDE with the built-in updater, the traffic doesn't go through the proxy, even though I have configured the proxy in the preferences. ### To reproduce --- ❗ A proxy server is not required to perform this demonstration. --- 1. Select **File > Preferences...** from the Arduino IDE menus. 1. Click the "**Network**" tab. 1. Select the "**Manual proxy configuration**" radio button. 1. Configure proxy as follows: - Select the "**HTTP**" radio button. - Set "**Host name**" to `example.com` - Set "**Port number**" to `42` - Set "**Username**" to `foo` - Set "**Password**" to `bar` 1. Click the <kbd>**OK**</kbd> button. 1. Trigger an IDE update. 🐛 The update is downloaded successfully, even though it should have failed if the invalid proxy configuration was used. ### Expected behavior The updater should also use the proxy setting in the Preferences. ### Arduino IDE version #### Original report 2.1.0 #### Last verified with 2.3.4 ### Operating system Windows ### Operating system version Windows 10 ### Additional context The configuration provided by the standardized [`http_proxy` and `https_proxy` environment variables](https://about.gitlab.com/blog/2021/01/27/we-need-to-talk-no-proxy/) are also not used by the updater. ### Issue checklist - [X] I searched for previous reports in [the issue tracker](https://github.com/arduino/arduino-ide/issues?q=) - [X] I verified the problem still occurs when using the latest [nightly build](https://www.arduino.cc/en/software#nightly-builds) - [X] My report contains all necessary details

This is in the Arduino IDE codebase, not in Arduino CLI, so will not be resolved by the platform installation fix that was made Arduino CLI.

So you will need to manually download new versions of Arduino IDE from the "Software" page instead of accepting the update offer from the notification that Arduino IDE displays when an new version of Arduino IDE is available. That notification does still serve a useful purpose in that it brings your attention to the availability of a new version.

Port Configuration Update

There is a bug that causes an update to the proxy's port number via the Preferences dialog to be ignored by Arduino IDE if you use:

github.com/arduino/arduino-ide

Proxy configuration not updated when only port number is changed

opened 10:50AM - 13 Dec 24 UTC

per1234

topic: code type: imperfection

### Describe the problem Users may access the Internet via a [proxy server](htt…ps://en.wikipedia.org/wiki/Proxy_server). Arduino IDE can be configured for this use case via the "**Network**" tab of the "**Preferences**" dialog. 🐛 If only the "**Port number**" preference is changed, the IDE disregards the change. ### To reproduce 1. Select **File > Preferences...** from the Arduino IDE menus. 1. Click the "**Network**" tab. 1. Select the "**Manual proxy configuration**" radio button. 1. Configure proxy as follows: - Select the "**HTTP**" radio button. - Set "**Host name**" to `example.com` - Set "**Port number**" to `42` - Set "**Username**" to `foo` - Set "**Password**" to `bar` 1. Click the <kbd>**OK**</kbd> button. 1. Select **File > Preferences...** from the Arduino IDE menus. 1. Click the "**Network**" tab. 🙂 The proxy configuration is as you specified at step (4). 1. Change "**Port number**" to `123`. 1. Click the <kbd>**OK**</kbd> button. 1. Select **File > Preferences...** from the Arduino IDE menus. 1. Click the "**Network**" tab. 🐛 The value of the "**Port number**" preference is `42` as configured at step (4) instead of `123` as reconfigured at step (8). ### Expected behavior Changes to the "**Port number**" preference take effect. ### Arduino IDE version #### Original report 2.2.2-nightly-20240119 #### Last verified with 2.3.4 ### Operating system Windows ### Operating system version Windows 11 ### Additional context The fault does not occur if other proxy preferences are changed at the same time as the "**Port number**" preference. --- Originally reported by @lokomiro ### Issue checklist - [X] I searched for previous reports in [the issue tracker](https://github.com/arduino/arduino-ide/issues?q=) - [X] I verified the problem still occurs when using the latest [nightly build](https://www.arduino.cc/en/software#nightly-builds) - [X] My report contains all necessary details

If you find the need to change the port number, the workaround will be to make the change by editing the configuration in arduino-cli.yaml.

Firmware Updater Does Not Use Proxy

Arduino IDE has a "Firmware Updater" feature:

https://docs.arduino.cc/software/ide-v2/tutorials/ide-v2-fw-cert-uploader#firmware-updater

This feature relies on being able to download the firmware file from the Internet. Unfortunately proxy support has not been implemented in the Arduino Firmware Uploader helper tool that performs that download. The firmware updater feature is only relevant to a few official Arduino boards (e.g., Arduino UNO R4 WiFi) that have a supplemental module running a custom firmware maintained by Arduino. So, depending on which boards you work with, you might not be affected by this bug. If you find you are affected, please make a post here on Arduino Forum and we'll help you find an alternative method to update the firmware.

The Arduino IDE developers are tracking this bug here:

github.com/arduino/arduino-ide

IDE doesn't start when proxy configuration is required to access network

opened 09:42AM - 15 Sep 22 UTC

fpistm

topic: code type: imperfection

### Describe the problem I've installed the new official release 2.0.0 (on Wind…ows 10 and Linux Ubuntu 20.04 LTS) from archive. When launching it, I got this windows and nothing happen. ![image](https://user-images.githubusercontent.com/20641798/190361780-4f34e292-9f61-48bc-8221-1e8d08456889.png) The logs show it fails when network access are performed: ```text Starting backend process. PID: 669267 [669288:0915/110646.964823:ERROR:sandbox_linux.cc(374)] InitializeSandbox() called with multiple threads in process gpu-process. Using browser-only version of superagent in non-browser environment Configuring to accept webviews on '^.+\.webview\..+$' hostname. root INFO Configuration directory URI: 'file:///local/home/<username>/.theia' root INFO Backend Object.initialize: 7.4 ms [Finished 1.227 s after backend start] root INFO Backend Object.configure: 5.7 ms [Finished 1.227 s after backend start] root INFO Backend MessagingContribution.onStart: 2.9 ms [Finished 1.227 s after backend start] root INFO Backend OSBackendApplicationContribution.configure: 0.7 ms [Finished 1.293 s after backend start] root INFO Backend DefaultWorkspaceServer.onStart: 0.6 ms [Finished 1.293 s after backend start] root INFO Backend LocalizationBackendContribution.configure: 0.3 ms [Finished 1.294 s after backend start] root WARN Backend LocalizationBackendContribution.initialize took longer than the expected maximum 50 milliseconds: 66.3 ms [Finished 1.294 s after backend start] root INFO Backend TaskBackendApplicationContribution.onStart: 0.5 ms [Finished 1.294 s after backend start] root INFO Backend ElectronTokenBackendContribution.configure: 1.7 ms [Finished 1.296 s after backend start] root INFO Backend PluginDeployerContribution.initialize: 0.8 ms [Finished 1.297 s after backend start] root INFO Backend ConfigServiceImpl.onStart: 1.4 ms [Finished 1.298 s after backend start] root INFO Backend WebviewBackendSecurityWarnings.initialize: 0.7 ms [Finished 1.299 s after backend start] root INFO Backend ArduinoDaemonImpl.onStart: 1.6 ms [Finished 1.300 s after backend start] root INFO Backend NodeFileUploadService.configure: 2.9 ms [Finished 1.301 s after backend start] daemon INFO Starting daemon from /local/data/ide/arduino/arduino_2.0.0/resources/app/node_modules/arduino-ide-extension/build/arduino-cli... discovery-log INFO start discovery-log INFO start new deferred root INFO Backend BoardDiscovery.onStart: 1.5 ms [Finished 1.303 s after backend start] root INFO Backend FileDownloadEndpoint.configure: 0.8 ms [Finished 1.303 s after backend start] root INFO Backend AuthenticationServiceImpl.onStart: 0.7 ms [Finished 1.305 s after backend start] root INFO Backend PluginApiContribution.configure: 0.8 ms [Finished 1.305 s after backend start] root INFO Backend HostedPluginReader.configure: 0.4 ms [Finished 1.306 s after backend start] root INFO Backend HostedPluginReader.configure: 0.2 ms [Finished 1.306 s after backend start] root INFO Backend PlotterBackendContribution.configure: 0.5 ms [Finished 1.307 s after backend start] root INFO Theia app listening on http://localhost:35383. root INFO Finished starting backend application: 5.4 ms [Finished 1.311 s after backend start] root WARN The local plugin referenced by local-dir:/local/home/<username>/.arduinoIDE/plugins does not exist. root WARN The local plugin referenced by local-dir:/local/home/<username>/.arduinoIDE/extensions does not exist. root WARN The local plugin referenced by local-dir:/local/home/<username>/.arduinoProIDE/plugins does not exist. root INFO PluginTheiaDirectoryHandler: accepting plugin with path root INFO Resolved "cortex-debug" to a VS Code extension "cortex-debug@0.3.10" with engines: root INFO PluginTheiaDirectoryHandler: accepting plugin with path root INFO Resolved "vscode-arduino-tools" to a VS Code extension "vscode-arduino-tools@0.0.2-beta.5" with engines: root INFO PluginTheiaDirectoryHandler: accepting plugin with path root INFO Resolved "vscode-builtin-cpp" to a VS Code extension "cpp@1.52.1" with engines: root INFO PluginTheiaDirectoryHandler: accepting plugin with path root INFO Resolved "vscode-builtin-json" to a VS Code extension "json@1.46.1" with engines: root INFO PluginTheiaDirectoryHandler: accepting plugin with path root INFO Resolved "vscode-builtin-json-language-features" to a VS Code extension "json-language-features@1.46.1" with engines: root INFO PluginTheiaDirectoryHandler: accepting plugin with path root INFO Resolved "vscode-language-pack-cs" to a VS Code extension "vscode-language-pack-cs@1.69.0" with engines: root INFO PluginTheiaDirectoryHandler: accepting plugin with path root INFO Resolved "vscode-language-pack-de" to a VS Code extension "vscode-language-pack-de@1.69.0" with engines: root INFO PluginTheiaDirectoryHandler: accepting plugin with path root INFO Resolved "vscode-language-pack-es" to a VS Code extension "vscode-language-pack-es@1.69.0" with engines: root INFO PluginTheiaDirectoryHandler: accepting plugin with path root INFO Resolved "vscode-language-pack-fr" to a VS Code extension "vscode-language-pack-fr@1.69.0" with engines: root INFO PluginTheiaDirectoryHandler: accepting plugin with path root INFO Resolved "vscode-language-pack-it" to a VS Code extension "vscode-language-pack-it@1.69.0" with engines: root INFO PluginTheiaDirectoryHandler: accepting plugin with path root INFO Resolved "vscode-language-pack-ja" to a VS Code extension "vscode-language-pack-ja@1.69.0" with engines: root INFO PluginTheiaDirectoryHandler: accepting plugin with path root INFO Resolved "vscode-language-pack-nl" to a VS Code extension "vscode-language-pack-nl@1.48.3" with engines: root INFO PluginTheiaDirectoryHandler: accepting plugin with path root INFO Resolved "vscode-language-pack-pt-BR" to a VS Code extension "vscode-language-pack-pt-BR@1.69.0" with engines: root INFO PluginTheiaDirectoryHandler: accepting plugin with path root INFO Resolved "vscode-language-pack-ru" to a VS Code extension "vscode-language-pack-ru@1.69.0" with engines: root INFO PluginTheiaDirectoryHandler: accepting plugin with path root INFO Resolved "vscode-language-pack-tr" to a VS Code extension "vscode-language-pack-tr@1.69.0" with engines: root INFO PluginTheiaDirectoryHandler: accepting plugin with path root INFO Resolved "vscode-language-pack-zh-hans" to a VS Code extension "vscode-language-pack-zh-hans@1.69.0" with engines: daemon INFO {"level":"info","msg":"Using config file: /local/home/<username>/.arduinoIDE/arduino-cli.yaml","time":"2022-09-15T11:06:48+02:00"} {"level":"info","msg":"arduino-cli version 0.27.1","time":"2022-09-15T11:06:48+02:00"} {"level":"info","msg":"Executing `arduino-cli daemon`","time":"2022-09-15T11:06:48+02:00"} {"IP":"127.0.0.1","Port":"36433"} daemon INFO Daemon is running. root INFO ---- DURATION: loadCliConfig took 69.967 ms. Args: [] ---- daemon INFO {"level":"info","msg":"Loading hardware from: /local/home/<username>/.arduino15/packages","time":"2022-09-15T11:06:48+02:00"} daemon INFO {"index":"/local/home/<username>/.arduino15/library_index.json","level":"info","msg":"Loading libraries index file","time":"2022-09-15T11:06:48+02:00"} {"dir":"/local/home/<username>/.arduino15/libraries","level":"info","location":"ide","msg":"Adding libraries dir","time":"2022-09-15T11:06:48+02:00"} {"dir":"/local/home/<username>/Arduino/libraries","level":"info","location":"user","msg":"Adding libraries dir","time":"2022-09-15T11:06:48+02:00"} root ERROR Detected an error response during the gRPC core client initialization: code: 9, message: Loading index file: loading json index file /local/home/<username>/.arduino15/package_index.json: open /local/home/<username>/.arduino15/package_index.json: no such file or directory root ERROR Detected an error response during the gRPC core client initialization: code: 9, message: Error loading hardware platform: discovery builtin:serial-discovery not found root ERROR Detected an error response during the gRPC core client initialization: code: 9, message: Error loading hardware platform: discovery builtin:mdns-discovery not found root ERROR Detected an error response during the gRPC core client initialization: code: 9, message: Loading index file: reading library_index.json: open /local/home/<username>/.arduino15/library_index.json: no such file or directory root ERROR The primary packages indexes are missing. Running indexes update before initializing the core gRPC client daemon INFO {"level":"info","msg":"Updating libraries index","time":"2022-09-15T11:06:48+02:00"} {"level":"info","msg":"URL: https://downloads.arduino.cc/packages/package_index.tar.bz2","time":"2022-09-15T11:06:48+02:00"} {"level":"info","msg":"Updating index","time":"2022-09-15T11:06:48+02:00","url":{"Scheme":"https","Opaque":"","User":null,"Host":"downloads.arduino.cc","Path":"/packages/package_index.tar.bz2","RawPath":"","ForceQuery":false,"RawQuery":"","Fragment":"","RawFragment":""}} ``` #### Third step: So I've added manually the proxy setting in the newly created config `~/.arduinoIDE/arduino-cli.yaml` (linux) ```yaml network: proxy: http://<username>:<password>@<proxy>:<port> ``` Finally I was able to get the IDE properly started. ### To reproduce Works behind a proxy. ### Expected behavior - Warn user properly instead of having empty windows with 'splashscreen' or proposed to configure network proxy. - Document proxy settings requirements for Arduino IDE 2.0.0 Maybe partially linked to arduino/arduino-ide#29 ### Arduino IDE version 2.0.0 ### Operating system - Windows - Linux ### Operating system version - Windows 10 - Ubuntu 20.04 LTS ### Additional context <a name="workaround"></a> #### Workaround 1. Select **File > Quit** from the Arduino IDE menus if it is running. 1. Use any text editor to open the file at the following path: - **Windows:** ```text C:\Users\<username>\.arduinoIDE\arduino-cli.yaml ``` (where `<username>` is your Windows username) - **Linux:** ```text ~/.arduinoIDE/arduino-cli.yaml ``` ❗ The `~/.arduinoIDE/` folder may be hidden by default in your file manager and terminal. - **macOS:** ```text ~/.arduinoIDE/arduino-cli.yaml ``` ❗ The `~/.arduinoIDE/` folder is hidden by default. You can make it visible by pressing the <kbd>**Command**</kbd>+<kbd>**Shift**</kbd>+<kbd>**.**</kbd> keyboard shortcut. 1. Add the following lines anywhere in the file: ```yaml network: proxy: <proxy scheme>://<username>:<password>@<proxy address>:<port> ``` Where the placeholders are: - `<proxy scheme>`: the URL scheme for your proxy server. One of the following: - `http` - `socks5` - `<username>`: the username of your proxy server credentials. - `<password>`: the password of your proxy server credentials. - `<proxy address>`: the address of your proxy server. - `<port>`: the port of your proxy server. 1. Save the file. 1. Start Arduino IDE. #### Additional reports - https://github.com/arduino/arduino-ide/issues/1438#issuecomment-1386600707 - https://github.com/arduino/arduino-ide/issues/1438#issuecomment-1577988752 - https://github.com/arduino/arduino-ide/issues/1438#issuecomment-1722883600 - https://github.com/arduino/arduino-ide/issues/2139 - https://github.com/arduino/arduino-ide/issues/2312 - https://github.com/arduino/arduino-ide/issues/2705 - https://forum.arduino.cc/t/arduino-ide-doesnt-get-any-further-than-splash-screen/1084721 - https://forum.arduino.cc/t/2-0-0-not-loading-windows-10/1035264 - https://forum.arduino.cc/t/arduino-2-0-will-not-start-past-the-loading-screen/1049023/9 - https://forum.arduino.cc/t/adding-a-root-cert-to-the-ide-keystore/1085491/3 - https://forum.arduino.cc/t/v2-0-x-on-linux-behind-proxy/1089208 - https://forum.arduino.cc/t/arduino-2-x-proxy-system-settings/1169532 - https://forum.arduino.cc/t/ide-hangs-on-startup-library-index-json-the-system-cannot-find-the-file-specified/1249757 - https://forum.arduino.cc/t/ide-hangs-on-startup-wsarecv-une-connexion-existante/1330940 #### Related - https://github.com/arduino/arduino-ide/issues/29 - https://github.com/arduino/arduino-ide/issues/2042 - https://github.com/arduino/arduino-cli/issues/1762 ### Issue checklist - [X] I searched for previous reports in [the issue tracker](https://github.com/arduino/arduino-ide/issues?q=) - [X] I verified the problem still occurs when using the latest [nightly build](https://github.com/arduino/arduino-ide#nightly-builds) - [X] My report contains all necessary details

As you are aware, the workaround for that specific bug is to configure the proxy via the network.proxy key in the arduino-cli.yaml file.

Of course the bug I mentioned above renders even that workaround futile, but that issue is separate from the bug that causes Arduino IDE to fail to start up under these conditions.

nxfltn · September 19, 2025, 1:36am

Version 2.3.2 worked, thank you very much.

One note for people who may find this: you must manually delete the app configuration folder C:\Users\<username>\.arduinoIDE left from version 2.3.6 before installing version 2.3.2

ptillisch · September 19, 2025, 1:41am

You are welcome. I'm glad it is working now.

Regards, Per

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Rant about IDE 2.X proxy issues on Windows (but also on Linux and MacOS)

Explanation

Workaround

Use Older Version of Arduino IDE

Use Arduino CLI to Install Platforms

Other Proxy Handling Bugs

IDE Updates

Port Configuration Update

Firmware Updater Does Not Use Proxy

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