IDE hangs on startup: "wsarecv: An existing connection was forcibly closed by the remote host."

Development Tools IDE 2.x
1

Fresh install of the IDE on my laptop (windows 10) fails to launch.
Another thread said to launch it via powershell to get errors but mine don't seem to match.

Arduino IDE 2.3.6
Checking for frontend application configuration customizations. Module path: C:\Program Files\Arduino IDE\resources\app\lib\backend\electron-main.js, destination 'package.json': C:\Program Files\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}${appName}","files.autoSave":"afterDelay","editor.minimap.enabled":false,"editor.tabSize":2,"editor.scrollBeyondLastLine":false,"editor.quickSuggestions":{"other":false,"comments":false,"strings":false},"editor.maxTokenizationLineLength":500,"editor.bracketPairColorization.enabled":false,"breadcrumbs.enabled":false,"workbench.tree.renderIndentGuides":"none","explorer.compactFolders":false},"appVersion":"2.3.6","cliVersion":"1.2.0","buildDate":"2025-04-09T11:26:55.498Z"}
Starting backend process. PID: 22356
Showing main window early
Using browser-only version of superagent in non-browser environment
Configuration directory URI: 'file:///c%3A/Users/Gordon/.arduinoIDE'
Configuring to accept webviews on '^.+\.webview\..+$' hostname.
2025-06-28T21:31:37.913Z root INFO Backend u.initialize: 23.4 ms [Finished 0.454 s after backend start]
2025-06-28T21:31:37.914Z root INFO Backend Object.initialize: 22.2 ms [Finished 0.454 s after backend start]
2025-06-28T21:31:37.914Z root INFO Backend a.initialize: 1.2 ms [Finished 0.454 s after backend start]
2025-06-28T21:31:37.914Z root INFO Backend a.initialize: 0.9 ms [Finished 0.454 s after backend start]
2025-06-28T21:31:37.914Z root INFO Backend u.initialize: 1.2 ms [Finished 0.455 s after backend start]
2025-06-28T21:31:37.915Z root INFO Backend l.initialize: 23.2 ms [Finished 0.455 s after backend start]
2025-06-28T21:31:37.921Z root INFO configured all backend app contributions
2025-06-28T21:31:37.921Z root INFO Backend l.onStart: 1.0 ms [Finished 0.463 s after backend start]
2025-06-28T21:31:37.921Z root INFO Backend d.onStart: 0.1 ms [Finished 0.463 s after backend start]
2025-06-28T21:31:37.922Z root INFO Backend a.onStart: 0.3 ms [Finished 0.464 s after backend start]
2025-06-28T21:31:37.922Z config INFO >>> Initializing CLI configuration...
2025-06-28T21:31:37.922Z root INFO Backend x.onStart: 0.3 ms [Finished 0.464 s after backend start]
2025-06-28T21:31:37.922Z config INFO Loading CLI configuration from c:\Users\Gordon\.arduinoIDE\arduino-cli.yaml...
2025-06-28T21:31:37.922Z daemon INFO Starting daemon from C:\Program Files\Arduino IDE\resources\app\lib\backend\resources\arduino-cli.exe...
2025-06-28T21:31:37.922Z root INFO Backend w.onStart: 0.4 ms [Finished 0.465 s after backend start]
2025-06-28T21:31:37.922Z discovery-log INFO start
2025-06-28T21:31:37.922Z discovery-log INFO start new deferred
2025-06-28T21:31:37.922Z root INFO Backend v.onStart: 0.2 ms [Finished 0.465 s after backend start]
2025-06-28T21:31:37.922Z root INFO Backend a.onStart: 0.1 ms [Finished 0.465 s after backend start]
2025-06-28T21:31:37.931Z root INFO Theia app listening on http://127.0.0.1:62434.
2025-06-28T21:31:37.931Z root INFO Finished starting backend application: 8.8 ms [Finished 0.474 s after backend start]
2025-06-28T21:31:37.932Z root WARN The local plugin referenced by local-dir:/c%3A/Users/Gordon/.arduinoIDE/plugins does not exist.
2025-06-28T21:31:37.932Z root WARN The local plugin referenced by local-dir:/c%3A/Users/Gordon/.arduinoIDE/deployedPlugins does not exist.
2025-06-28T21:31:37.932Z root WARN The local plugin referenced by local-dir:C:\Users\Gordon\.arduinoIDE\plugins does not exist.
2025-06-28T21:31:37.941Z config INFO Loaded CLI configuration: {"board_manager":{"additional_urls":[]}}
2025-06-28T21:31:37.941Z config INFO Loading fallback CLI configuration to get 'directories.data' and 'directories.user'2025-06-28T21:31:37.971Z root INFO Resolve plugins list: 48.0 ms [Finished 0.514 s after backend start]
2025-06-28T21:31:37.983Z daemon INFO time="2025-06-28T16:31:37-05:00" level=info msg="arduino-cli version 1.2.0"
2025-06-28T21:31:37.983Z daemon INFO time="2025-06-28T16:31:37-05:00" level=info msg="Using config file: c:\\Users\\Gordon\\.arduinoIDE\\arduino-cli.yaml"
time="2025-06-28T16:31:37-05:00" level=info msg="Executing `arduino-cli daemon`"
2025-06-28T21:31:37.996Z daemon INFO Daemon is now listening on 127.0.0.1:62435
{"IP":"127.0.0.1","Port":"62435"}
2025-06-28T21:31:37.996Z daemon INFO Daemon is running.
2025-06-28T21:31:38.003Z config INFO Loaded fallback CLI configuration: {"directories":{"user":"C:\\Users\\Gordon\\Documents\\Arduino","data":"C:\\Users\\Gordon\\AppData\\Local\\Arduino15"}}
2025-06-28T21:31:38.003Z config INFO Merged CLI configuration with the fallback: {"directories":{"user":"C:\\Users\\Gordon\\Documents\\Arduino","data":"C:\\Users\\Gordon\\AppData\\Local\\Arduino15"},"board_manager":{"additional_urls":[]}}
2025-06-28T21:31:38.003Z config INFO Loaded the CLI configuration.
2025-06-28T21:31:38.009Z config INFO Mapped the CLI configuration: {"dataDirUri":"file:///c%3A/Users/Gordon/AppData/Local/Arduino15","sketchDirUri":"file:///c%3A/Users/Gordon/Documents/Arduino","additionalUrls":[],"network":"none","locale":"en"}
2025-06-28T21:31:38.009Z config INFO Validating the CLI configuration...
2025-06-28T21:31:38.009Z config INFO The CLI config is valid.
2025-06-28T21:31:38.009Z config INFO <<< Initialized the CLI configuration.
2025-06-28T21:31:38.014Z daemon INFO time="2025-06-28T16:31:38-05:00" level=info msg="Updating index" url="https://downloads.arduino.cc/packages/package_index.tar.bz2"
2025-06-28T21:31:38.016Z daemon INFO time="2025-06-28T16:31:38-05:00" level=info msg="Starting download" url="https://downloads.arduino.cc/packages/package_index.tar.bz2"
2025-06-28T21:31:38.069Z root ERROR Detected an error response during the gRPC core client initialization: code: 3, message: Some indexes could not be updated.
2025-06-28T21:31:38.069Z root ERROR Detected an error response during the gRPC core client initialization: code: 9, message: Loading index file: loading json index file C:\Users\Gordon\AppData\Local\Arduino15\package_index.json: open C:\Users\Gordon\AppData\Local\Arduino15\package_index.json: The system cannot find the file specified.
2025-06-28T21:31:38.070Z 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
2025-06-28T21:31:38.070Z 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
2025-06-28T21:31:38.070Z daemon INFO time="2025-06-28T16:31:38-05:00" level=info msg="Loading hardware from: C:\\Users\\Gordon\\AppData\\Local\\Arduino15\\packages"
time="2025-06-28T16:31:38-05:00" level=info msg="Loading libraries index file" index="C:\\Users\\Gordon\\AppData\\Local\\Arduino15\\library_index.json"
2025-06-28T21:31:38.265Z daemon INFO time="2025-06-28T16:31:38-05:00" level=info msg="Adding libraries dir" dir="C:\\Users\\Gordon\\AppData\\Local\\Arduino15\\libraries" isSingleLibrary=false location=ide
time="2025-06-28T16:31:38-05:00" level=info msg="Adding libraries dir" dir="C:\\Users\\Gordon\\Documents\\Arduino\\libraries" isSingleLibrary=false location=user
2025-06-28T21:31:38.267Z root ERROR The primary packages indexes are missing. Running indexes update before initializing the core gRPC client The index of the cores and libraries must be updated before initializing the core gRPC client.
The following problems were detected during the gRPC client initialization:
[platform-index] - code: 9, message: Loading index file: loading json index file C:\Users\Gordon\AppData\Local\Arduino15\package_index.json: open C:\Users\Gordon\AppData\Local\Arduino15\package_index.json: The system cannot find the file specified.
[platform-index] - code: 9, message: Error loading hardware platform: discovery builtin:serial-discovery not found
[platform-index] - code: 9, message: Error loading hardware platform: discovery builtin:mdns-discovery not found

2025-06-28T21:31:38.268Z daemon INFO time="2025-06-28T16:31:38-05:00" level=info msg="Updating index" url="https://downloads.arduino.cc/packages/package_index.tar.bz2"
2025-06-28T21:31:38.268Z daemon INFO time="2025-06-28T16:31:38-05:00" level=info msg="Starting download" url="https://downloads.arduino.cc/packages/package_index.tar.bz2"
2025-06-28T21:31:38.269Z root INFO core-client-provider [platform-index] Downloading index: package_index.tar.bz2

2025-06-28T21:31:38.308Z root INFO Deploy plugins list: 384.8 ms [Finished 0.851 s after backend start]
2025-06-28T21:31:38.314Z root ERROR Failed to update platform indexes. Error: 13 INTERNAL: Some indexes could not be updated.
    at t.callErrorFromStatus (C:\Program Files\Arduino IDE\resources\app\lib\backend\main.js:2:3089094)
    at Object.onReceiveStatus (C:\Program Files\Arduino IDE\resources\app\lib\backend\main.js:2:6681994)
    at Object.onReceiveStatus (C:\Program Files\Arduino IDE\resources\app\lib\backend\main.js:2:2571739)
    at C:\Program Files\Arduino IDE\resources\app\lib\backend\main.js:2:4307911
    at process.processTicksAndRejections (node:internal/process/task_queues:77:11)
for call at
    at s.makeServerStreamRequest (C:\Program Files\Arduino IDE\resources\app\lib\backend\main.js:2:6681761)
    at s.updateIndex (C:\Program Files\Arduino IDE\resources\app\lib\backend\main.js:2:3088187)
    at C:\Program Files\Arduino IDE\resources\app\lib\backend\main.js:2:6284829
    at C:\Program Files\Arduino IDE\resources\app\lib\backend\main.js:2:6285177
    at new Promise (<anonymous>)
    at y.doUpdateIndex (C:\Program Files\Arduino IDE\resources\app\lib\backend\main.js:2:6285156)
    at y.updatePlatformIndex (C:\Program Files\Arduino IDE\resources\app\lib\backend\main.js:2:6284801)
    at y.updateIndex (C:\Program Files\Arduino IDE\resources\app\lib\backend\main.js:2:6284169)
    at y.initInstanceWithFallback (C:\Program Files\Arduino IDE\resources\app\lib\backend\main.js:2:6282462)
    at process.processTicksAndRejections (node:internal/process/task_queues:95:5)
2025-06-28T21:31:38.315Z daemon INFO time="2025-06-28T16:31:38-05:00" level=info msg="Updating index" url="https://downloads.arduino.cc/packages/package_index.tar.bz2"
2025-06-28T21:31:38.316Z daemon INFO time="2025-06-28T16:31:38-05:00" level=info msg="Starting download" url="https://downloads.arduino.cc/packages/package_index.tar.bz2"
2025-06-28T21:31:38.829Z daemon INFO time="2025-06-28T16:31:38-05:00" level=info msg="Checking signature" index="C:\\Users\\Gordon\\AppData\\Local\\Arduino15\\package_index.json" signatureFile="C:\\Users\\Gordon\\AppData\\Local\\Arduino15\\package_index.json.sig" trusted=true
2025-06-28T21:31:38.830Z daemon INFO time="2025-06-28T16:31:38-05:00" level=info msg="Loading hardware from: C:\\Users\\Gordon\\AppData\\Local\\Arduino15\\packages"
2025-06-28T21:31:38.830Z daemon INFO time="2025-06-28T16:31:38-05:00" level=info msg="Starting download" url="https://downloads.arduino.cc/discovery/serial-discovery/serial-discovery_v1.4.1_Windows_64bit.zip"
2025-06-28T21:31:38.872Z root ERROR Detected an error response during the gRPC core client initialization: code: 13, message: downloading builtin:serial-discovery@1.4.1 tool: Get "https://downloads.arduino.cc/discovery/serial-discovery/serial-discovery_v1.4.1_Windows_64bit.zip": read tcp [2600:1702:1010:21c0:4d27:651f:9cba:b906]:62446->[2606:4700::6812:a15]:443: wsarecv: An existing connection was forcibly closed by the remote host.
2025-06-28T21:31:38.872Z daemon INFO time="2025-06-28T16:31:38-05:00" level=info msg="Starting download" url="https://downloads.arduino.cc/monitor/serial-monitor/serial-monitor_v0.15.0_Windows_64bit.zip"
2025-06-28T21:31:38.913Z 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": read tcp [2600:1702:1010:21c0:4d27:651f:9cba:b906]:62447->[2606:4700::6812:a15]:443: wsarecv: An existing connection was forcibly closed by the remote host.
2025-06-28T21:31:38.913Z daemon INFO time="2025-06-28T16:31:38-05:00" level=info msg="Starting download" url="https://downloads.arduino.cc/tools/ctags-5.8-arduino11-pm-i686-mingw32.zip"
2025-06-28T21:31:38.955Z 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": read tcp [2600:1702:1010:21c0:4d27:651f:9cba:b906]:62448->[2606:4700::6812:a15]:443: wsarecv: An existing connection was forcibly closed by the remote host.
2025-06-28T21:31:38.955Z daemon INFO time="2025-06-28T16:31:38-05:00" level=info msg="Starting download" url="https://downloads.arduino.cc/discovery/dfu-discovery/dfu-discovery_v0.1.2_Windows_64bit.zip"
2025-06-28T21:31:38.996Z 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": read tcp [2600:1702:1010:21c0:4d27:651f:9cba:b906]:62449->[2606:4700::6812:a15]:443: wsarecv: An existing connection was forcibly closed by the remote host.
2025-06-28T21:31:38.996Z daemon INFO time="2025-06-28T16:31:38-05:00" level=info msg="Starting download" url="https://downloads.arduino.cc/discovery/mdns-discovery/mdns-discovery_v1.0.9_Windows_64bit.zip"
2025-06-28T21:31:39.024Z root INFO creating connection for 1
2025-06-28T21:31:39.038Z 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": read tcp [2600:1702:1010:21c0:4d27:651f:9cba:b906]:62450->[2606:4700::6812:a15]:443: wsarecv: An existing connection was forcibly closed by the remote host.
2025-06-28T21:31:39.038Z root ERROR Detected an error response during the gRPC core client initialization: code: 9, message: Error loading hardware platform: reading directory C:\Users\Gordon\AppData\Local\Arduino15\packages\builtin\tools: open C:\Users\Gordon\AppData\Local\Arduino15\packages\builtin\tools: The system cannot find the path specified.
2025-06-28T21:31:39.038Z daemon INFO time="2025-06-28T16:31:39-05:00" level=info msg="Loading tools from dir: C:\\Users\\Gordon\\AppData\\Local\\Arduino15\\packages\\builtin\\tools"
2025-06-28T21:31:39.049Z daemon INFO time="2025-06-28T16:31:39-05:00" level=info msg="Loading libraries index file" index="C:\\Users\\Gordon\\AppData\\Local\\Arduino15\\library_index.json"
2025-06-28T21:31:39.049Z root ERROR Detected an error response during the gRPC core client initialization: code: 9, message: Error loading hardware platform: discovery builtin:serial-discovery not installed
2025-06-28T21:31:39.049Z root ERROR Detected an error response during the gRPC core client initialization: code: 9, message: Error loading hardware platform: discovery builtin:mdns-discovery not installed
2025-06-28T21:31:39.214Z daemon INFO time="2025-06-28T16:31:39-05:00" level=info msg="Adding libraries dir" dir="C:\\Users\\Gordon\\AppData\\Local\\Arduino15\\libraries" isSingleLibrary=false location=ide
2025-06-28T21:31:39.214Z daemon INFO time="2025-06-28T16:31:39-05:00" level=info msg="Adding libraries dir" dir="C:\\Users\\Gordon\\Documents\\Arduino\\libraries" isSingleLibrary=false location=user
2025-06-28T21:31:39.215Z root ERROR Uncaught Exception:  Error: The index of the cores and libraries must be updated before initializing the core gRPC client.
The following problems were detected during the gRPC client initialization:
[platform-index] - code: 9, message: Error loading hardware platform: discovery builtin:serial-discovery not installed
[platform-index] - code: 9, message: Error loading hardware platform: discovery builtin:mdns-discovery not installed

2025-06-28T21:31:39.215Z root ERROR Error: The index of the cores and libraries must be updated before initializing the core gRPC client.
The following problems were detected during the gRPC client initialization:
[platform-index] - code: 9, message: Error loading hardware platform: discovery builtin:serial-discovery not installed
[platform-index] - code: 9, message: Error loading hardware platform: discovery builtin:mdns-discovery not installed

    at C:\Program Files\Arduino IDE\resources\app\lib\backend\main.js:2:6283973
    at y.evaluateErrorStatus (C:\Program Files\Arduino IDE\resources\app\lib\backend\main.js:2:6283989)
    at process.processTicksAndRejections (node:internal/process/task_queues:95:5)
    at async a.<anonymous> (C:\Program Files\Arduino IDE\resources\app\lib\backend\main.js:2:6283659)
2025-06-28T21:31:39.719Z 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'.
2025-06-28T21:31:39.801Z root INFO Start frontend contributions: 230.7 ms [Finished 1.853 s after frontend start]
2025-06-28T21:31:39.802Z root INFO Changed application state from 'init' to 'started_contributions'.
2025-06-28T21:31:39.811Z root INFO Changed application state from 'started_contributions' to 'attached_shell'.
2025-06-28T21:31:39.811Z root INFO >>> Restoring the layout state...
2025-06-28T21:31:39.829Z root INFO [6aa3f87e-fde1-4279-b331-c3db250dbbfc] Waiting for backend deployment: 40.3 ms [Finished 1.889 s after frontend start]
2025-06-28T21:31:40.213Z root INFO [hosted-plugin: 25424] PLUGIN_HOST(25424) starting instance
[Object: null prototype] {}
2025-06-28T21:31:40.654Z root INFO [6aa3f87e-fde1-4279-b331-c3db250dbbfc] Sync of 23 plugins: 826.8 ms [Finished 2.716 s after frontend start]
[1280:0628/163142.539:ERROR:ssl_client_socket_impl.cc(879)] handshake failed; returned -1, SSL error code 1, net_error -101
[1280:0628/163142.580:ERROR:ssl_client_socket_impl.cc(879)] handshake failed; returned -1, SSL error code 1, net_error -101
2

Is your internet connection at home, or at work/school?

3

Home... I have been getting a lot of connection resets lately but it generally works without issue.

4

Hi @theundyingcode.

This problem might be caused by your firewall or some other network security system (e.g., proxy or VPN) interfering with Arduino IDE's ability to access the Internet.

Are you aware of anything special about the configuration of the network you connect to the Internet through that might interfere with Arduino IDE's access to the Internet?

5

There shouldn't be but, I wouldn't be surprised if something got flipped somewhere.

6

I ran the windows 10 network adapter reset and that seems to have fixed it. Ty for the help

7

You are welcome. I'm glad it is working now. Thanks for taking the time to post an update with your findings!