Arduino IDE 2.3.6 doesn't open

Development Tools IDE 2.x
1

Hi

I have installed Arduino IDE 2.3.6. Installation completed successfully. However running it just open a window with the Arduino logo.

Regards

2

Hi @erikvj. Please add a forum reply here to tell us which operating system you are using (e.g., "Windows")?

I ask for this information so that we can give you the appropriate instructions for your operating system.

3

Windows 11

4

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

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

Please do this:

  1. Close all Arduino IDE windows if the IDE is already running.
  2. Start Windows "File Explorer".
  3. 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)
      :red_exclamation_mark: 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".
  4. 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
  5. Select "Open PowerShell window here" from the menu.
    Windows PowerShell will now open with the current directory set to the Arduino IDE installation folder.
  6. Type the following command in the PowerShell window:
    & ".\Arduino IDE"
  7. Press the Enter key.
    Debug output should now be printed to the PowerShell window as Arduino IDE starts.
  8. 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).
  9. Switch back to the PowerShell window if the Arduino IDE window took the focus.
  10. Press the Ctrl+Shift+A keyboard shortcut.
    This will select all the text in the PowerShell window.
  11. Press the Ctrl+C keyboard shortcut.
    This will copy the contents of the PowerShell window to the clipboard.
  12. Open a reply here on this forum topic by clicking the "Reply" button.
  13. 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 toolbar
    Code block icon on toolbar390×118 4.25 KB
  14. Press the Ctrl+V keyboard shortcut.
    This will paste the output into the code block.
  15. Move the cursor outside of the code block markup before you add any additional text to your reply.
  16. Click the "Reply" button to publish the post.

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

5 
Windows PowerShell
Copyright (C) Microsoft Corporation. All rights reserved.

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

PS C:\Users\erikv\AppData\Local\Programs\Arduino IDE> & ".\Arduino IDE"
PS C:\Users\erikv\AppData\Local\Programs\Arduino IDE>
Arduino IDE 2.3.6
Checking for frontend application configuration customizations. Module path: C:\Users\erikv\AppData\Local\Programs\Arduino IDE\resources\app\lib\backend\electron-main.js, destination 'package.json': C:\Users\erikv\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}${appName}","files.autoSave":"afterDelay","editor.minimap.enabled":false,"editor.tabSize":2,"editor.scrollBeyondLastLine":false,"editor.quickSuggestions":{"other":false,"comments":false,"strings":false},"editor.maxTokenizationLineLength":500,"editor.bracketPairColorization.enabled":false,"breadcrumbs.enabled":false,"workbench.tree.renderIndentGuides":"none","explorer.compactFolders":false},"appVersion":"2.3.6","cliVersion":"1.2.0","buildDate":"2025-04-09T11:26:55.498Z"}
Starting backend process. PID: 15940
Showing main window early
Using browser-only version of superagent in non-browser environment
Configuration directory URI: 'file:///c%3A/Users/erikv/.arduinoIDE'
Configuring to accept webviews on '^.+\.webview\..+$' hostname.
2025-11-02T10:31:53.460Z root INFO Backend u.initialize: 33.2 ms [Finished 0.702 s after backend start]
2025-11-02T10:31:53.461Z root INFO Backend Object.initialize: 31.4 ms [Finished 0.702 s after backend start]
2025-11-02T10:31:53.461Z root INFO Backend a.initialize: 1.6 ms [Finished 0.702 s after backend start]
2025-11-02T10:31:53.461Z root INFO Backend a.initialize: 1.3 ms [Finished 0.702 s after backend start]
2025-11-02T10:31:53.461Z root INFO Backend u.initialize: 1.6 ms [Finished 0.702 s after backend start]
2025-11-02T10:31:53.465Z root INFO Backend l.initialize: 31.5 ms [Finished 0.703 s after backend start]
2025-11-02T10:31:53.472Z root INFO configured all backend app contributions
2025-11-02T10:31:53.473Z root INFO Backend l.onStart: 1.6 ms [Finished 0.716 s after backend start]
2025-11-02T10:31:53.474Z root INFO Backend d.onStart: 0.2 ms [Finished 0.716 s after backend start]
2025-11-02T10:31:53.475Z root INFO Backend a.onStart: 0.7 ms [Finished 0.717 s after backend start]
2025-11-02T10:31:53.475Z config INFO >>> Initializing CLI configuration...
2025-11-02T10:31:53.475Z root INFO Backend x.onStart: 0.6 ms [Finished 0.718 s after backend start]
2025-11-02T10:31:53.475Z config INFO Loading CLI configuration from c:\Users\erikv\.arduinoIDE\arduino-cli.yaml...
2025-11-02T10:31:53.475Z daemon INFO Starting daemon from C:\Users\erikv\AppData\Local\Programs\Arduino IDE\resources\app\lib\backend\resources\arduino-cli.exe...
2025-11-02T10:31:53.475Z root INFO Backend w.onStart: 0.5 ms [Finished 0.718 s after backend start]
2025-11-02T10:31:53.475Z discovery-log INFO start
2025-11-02T10:31:53.475Z discovery-log INFO start new deferred
2025-11-02T10:31:53.475Z root INFO Backend v.onStart: 0.3 ms [Finished 0.719 s after backend start]
2025-11-02T10:31:53.475Z root INFO Backend a.onStart: 0.1 ms [Finished 0.719 s after backend start]
2025-11-02T10:31:53.481Z root INFO Theia app listening on http://127.0.0.1:54719.
2025-11-02T10:31:53.481Z root INFO Finished starting backend application: 5.4 ms [Finished 0.724 s after backend start]
2025-11-02T10:31:53.491Z root WARN The local plugin referenced by local-dir:/c%3A/Users/erikv/.arduinoIDE/plugins does not exist.
2025-11-02T10:31:53.491Z root WARN The local plugin referenced by local-dir:/c%3A/Users/erikv/.arduinoIDE/deployedPlugins does not exist.
2025-11-02T10:31:53.491Z root WARN The local plugin referenced by local-dir:C:\Users\erikv\.arduinoIDE\plugins does not exist.
2025-11-02T10:31:53.506Z config INFO Loaded CLI configuration: {"board_manager":{"additional_urls":[]}}
2025-11-02T10:31:53.506Z config INFO Loading fallback CLI configuration to get 'directories.data' and 'directories.user'
2025-11-02T10:31:53.555Z root INFO Resolve plugins list: 77.4 ms [Finished 0.798 s after backend start]
2025-11-02T10:31:53.564Z daemon INFO time="2025-11-02T12:31:53+02:00" level=info msg="arduino-cli version 1.2.0"
2025-11-02T10:31:53.564Z daemon INFO time="2025-11-02T12:31:53+02:00" level=info msg="Using config file: c:\\Users\\erikv\\.arduinoIDE\\arduino-cli.yaml"
time="2025-11-02T12:31:53+02:00" level=info msg="Executing `arduino-cli daemon`"
2025-11-02T10:31:53.579Z daemon INFO Daemon is now listening on 127.0.0.1:54720
{"IP":"127.0.0.1","Port":"54720"}
2025-11-02T10:31:53.579Z daemon INFO Daemon is running.
2025-11-02T10:31:53.589Z config INFO Loaded fallback CLI configuration: {"directories":{"user":"C:\\Users\\erikv\\OneDrive\\Documents\\Arduino","data":"C:\\Users\\erikv\\AppData\\Local\\Arduino15"}}
2025-11-02T10:31:53.589Z config INFO Merged CLI configuration with the fallback: {"directories":{"user":"C:\\Users\\erikv\\OneDrive\\Documents\\Arduino","data":"C:\\Users\\erikv\\AppData\\Local\\Arduino15"},"board_manager":{"additional_urls":[]}}
2025-11-02T10:31:53.589Z config INFO Loaded the CLI configuration.
2025-11-02T10:31:53.598Z config INFO Mapped the CLI configuration: {"dataDirUri":"file:///c%3A/Users/erikv/AppData/Local/Arduino15","sketchDirUri":"file:///c%3A/Users/erikv/OneDrive/Documents/Arduino","additionalUrls":[],"network":"none","locale":"en"}
2025-11-02T10:31:53.598Z config INFO Validating the CLI configuration...
2025-11-02T10:31:53.604Z config INFO The CLI config is valid.
2025-11-02T10:31:53.604Z config INFO <<< Initialized the CLI configuration.
2025-11-02T10:31:53.608Z daemon INFO time="2025-11-02T12:31:53+02:00" level=info msg="Starting download" url="https://downloads.arduino.cc/libraries/library_index.tar.bz2"
2025-11-02T10:31:54.040Z root INFO Deploy plugins list: 563.3 ms [Finished 1.284 s after backend start]
2025-11-02T10:31:55.341Z root INFO creating connection for 1
2025-11-02T10:31:56.287Z root ERROR Detected an error response during the gRPC core client initialization: code: 3, message: Error verifying signature: signature expired: is your system clock set correctly?
2025-11-02T10:31:56.295Z daemon INFO time="2025-11-02T12:31:56+02:00" level=info msg="Checking signature" index="C:\\Users\\erikv\\AppData\\Local\\Arduino15\\package_index.json" signatureFile="C:\\Users\\erikv\\AppData\\Local\\Arduino15\\package_index.json.sig" trusted=true
time="2025-11-02T12:31:56+02:00" level=info msg="Loading hardware from: C:\\Users\\erikv\\AppData\\Local\\Arduino15\\packages"
time="2025-11-02T12:31:56+02:00" level=info msg="Loading package builtin from: C:\\Users\\erikv\\AppData\\Local\\Arduino15\\packages\\builtin"
2025-11-02T10:31:56.296Z daemon INFO time="2025-11-02T12:31:56+02:00" level=info msg="Checking existence of 'tools' path: C:\\Users\\erikv\\AppData\\Local\\Arduino15\\packages\\builtin\\tools"
time="2025-11-02T12:31:56+02:00" level=info msg="Loading tools from dir: C:\\Users\\erikv\\AppData\\Local\\Arduino15\\packages\\builtin\\tools"
2025-11-02T10:31:56.297Z daemon INFO time="2025-11-02T12:31:56+02:00" level=info msg="Loaded tool" tool="builtin:ctags@5.8-arduino11"
time="2025-11-02T12:31:56+02:00" level=info msg="Loaded tool" tool="builtin:dfu-discovery@0.1.2"
time="2025-11-02T12:31:56+02:00" level=info msg="Loaded tool" tool="builtin:mdns-discovery@1.0.9"
time="2025-11-02T12:31:56+02:00" level=info msg="Loaded tool" tool="builtin:serial-discovery@1.4.1"
time="2025-11-02T12:31:56+02:00" level=info msg="Loaded tool" tool="builtin:serial-monitor@0.15.0"
2025-11-02T10:31:56.300Z root WARN Frontend a.configure took longer than the expected maximum 100 milliseconds: 130.1 ms [Finished 2.174 s after frontend start]
2025-11-02T10:31:56.320Z daemon INFO time="2025-11-02T12:31:56+02:00" level=info msg="Loading libraries index file" index="C:\\Users\\erikv\\AppData\\Local\\Arduino15\\library_index.json"
2025-11-02T10:31:56.320Z daemon INFO time="2025-11-02T12:31:56+02:00" level=info msg="Adding libraries dir" dir="C:\\Users\\erikv\\AppData\\Local\\Arduino15\\libraries" isSingleLibrary=false location=ide
2025-11-02T10:31:56.321Z root ERROR Detected an error response during the gRPC core client initialization: code: 9, message: Loading index file: reading library_index.json: open C:\Users\erikv\AppData\Local\Arduino15\library_index.json: The system cannot find the file specified.
2025-11-02T10:31:56.321Z daemon INFO time="2025-11-02T12:31:56+02:00" level=info msg="Adding libraries dir" dir="C:\\Users\\erikv\\OneDrive\\Documents\\Arduino\\libraries" isSingleLibrary=false location=user
2025-11-02T10:31:56.325Z 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:
[library-index] - code: 9, message: Loading index file: reading library_index.json: open C:\Users\erikv\AppData\Local\Arduino15\library_index.json: The system cannot find the file specified.

2025-11-02T10:31:56.330Z root INFO core-client-provider [library-index] Downloading index: library_index.tar.bz2

2025-11-02T10:31:56.330Z daemon INFO time="2025-11-02T12:31:56+02:00" level=info msg="Starting download" url="https://downloads.arduino.cc/libraries/library_index.tar.bz2"
2025-11-02T10:31:56.338Z 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'.
2025-11-02T10:31:56.473Z root INFO Start frontend contributions: 358.8 ms [Finished 2.326 s after frontend start]
2025-11-02T10:31:56.473Z root INFO Changed application state from 'init' to 'started_contributions'.
2025-11-02T10:31:56.485Z root INFO Changed application state from 'started_contributions' to 'attached_shell'.
2025-11-02T10:31:56.485Z root INFO >>> Restoring the layout state...
2025-11-02T10:31:56.524Z root INFO [91984d7b-bc4c-47fb-8594-1c44d80220bc] Waiting for backend deployment: 76.0 ms [Finished 2.394 s after frontend start]
2025-11-02T10:31:57.185Z root INFO [hosted-plugin: 1560] PLUGIN_HOST(1560) starting instance
[Object: null prototype] {}
2025-11-02T10:31:57.804Z root INFO [91984d7b-bc4c-47fb-8594-1c44d80220bc] Sync of 23 plugins: 1285.3 ms [Finished 3.680 s after frontend start]
2025-11-02T10:31:58.742Z daemon INFO time="2025-11-02T12:31:58+02:00" level=info msg="Starting download" url="https://downloads.arduino.cc/libraries/library_index.tar.bz2"
2025-11-02T10:32:01.050Z root ERROR Detected an error response during the gRPC core client initialization: code: 3, message: Error verifying signature: signature expired: is your system clock set correctly?
2025-11-02T10:32:01.060Z daemon INFO time="2025-11-02T12:32:01+02:00" level=info msg="Checking signature" index="C:\\Users\\erikv\\AppData\\Local\\Arduino15\\package_index.json" signatureFile="C:\\Users\\erikv\\AppData\\Local\\Arduino15\\package_index.json.sig" trusted=true
2025-11-02T10:32:01.061Z daemon INFO time="2025-11-02T12:32:01+02:00" level=info msg="Loading hardware from: C:\\Users\\erikv\\AppData\\Local\\Arduino15\\packages"
2025-11-02T10:32:01.063Z daemon INFO time="2025-11-02T12:32:01+02:00" level=info msg="Loading package builtin from: C:\\Users\\erikv\\AppData\\Local\\Arduino15\\packages\\builtin"
2025-11-02T10:32:01.063Z daemon INFO time="2025-11-02T12:32:01+02:00" level=info msg="Checking existence of 'tools' path: C:\\Users\\erikv\\AppData\\Local\\Arduino15\\packages\\builtin\\tools"
time="2025-11-02T12:32:01+02:00" level=info msg="Loading tools from dir: C:\\Users\\erikv\\AppData\\Local\\Arduino15\\packages\\builtin\\tools"
2025-11-02T10:32:01.064Z daemon INFO time="2025-11-02T12:32:01+02:00" level=info msg="Loaded tool" tool="builtin:ctags@5.8-arduino11"
2025-11-02T10:32:01.064Z daemon INFO time="2025-11-02T12:32:01+02:00" level=info msg="Loaded tool" tool="builtin:dfu-discovery@0.1.2"
2025-11-02T10:32:01.064Z daemon INFO time="2025-11-02T12:32:01+02:00" level=info msg="Loaded tool" tool="builtin:mdns-discovery@1.0.9"
2025-11-02T10:32:01.064Z daemon INFO time="2025-11-02T12:32:01+02:00" level=info msg="Loaded tool" tool="builtin:serial-discovery@1.4.1"
2025-11-02T10:32:01.064Z daemon INFO time="2025-11-02T12:32:01+02:00" level=info msg="Loaded tool" tool="builtin:serial-monitor@0.15.0"
2025-11-02T10:32:01.080Z daemon INFO time="2025-11-02T12:32:01+02:00" level=info msg="Loading libraries index file" index="C:\\Users\\erikv\\AppData\\Local\\Arduino15\\library_index.json"
2025-11-02T10:32:01.080Z root ERROR Detected an error response during the gRPC core client initialization: code: 9, message: Loading index file: reading library_index.json: open C:\Users\erikv\AppData\Local\Arduino15\library_index.json: The system cannot find the file specified.
2025-11-02T10:32:01.081Z 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:
[library-index] - code: 9, message: Loading index file: reading library_index.json: open C:\Users\erikv\AppData\Local\Arduino15\library_index.json: The system cannot find the file specified.

2025-11-02T10:32:01.081Z 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:
[library-index] - code: 9, message: Loading index file: reading library_index.json: open C:\Users\erikv\AppData\Local\Arduino15\library_index.json: The system cannot find the file specified.

    at C:\Users\erikv\AppData\Local\Programs\Arduino IDE\resources\app\lib\backend\main.js:2:6283973
    at y.evaluateErrorStatus (C:\Users\erikv\AppData\Local\Programs\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:\Users\erikv\AppData\Local\Programs\Arduino IDE\resources\app\lib\backend\main.js:2:6283659)
2025-11-02T10:32:01.081Z daemon INFO time="2025-11-02T12:32:01+02:00" level=info msg="Adding libraries dir" dir="C:\\Users\\erikv\\AppData\\Local\\Arduino15\\libraries" isSingleLibrary=false location=ide
time="2025-11-02T12:32:01+02:00" level=info msg="Adding libraries dir" dir="C:\\Users\\erikv\\OneDrive\\Documents\\Arduino\\libraries" isSingleLibrary=false location=user
6

The cause of the problem is that your system time is incorrect. You can fix it by syncing the system time. I'll provide instructions you can follow to do that:

  1. Right click the Windows Start icon (⊞) on the taskbar.
    A context menu will open.
  2. Select "Settings" from the context menu.
    Windows "Settings" will open.
  3. Select "Time & language" from the navigation panel on the left side of the window.
  4. Select "Date & time" from the list at the right side of the Settings window.
    The "Date & time" settings section will expand.
  5. Click the "Sync now" button that is located under the "Additional settings" section of the window.
  6. Wait for the syncing process to finish.
  7. Close any Arduino IDE windows that are open.
  8. Start Arduino IDE again, as usual.
    ⓘ It is not required to start the IDE from the PowerShell terminal this time.

This time Arduino IDE should start up fully and work as expected.

7

All working. Thanks!

8

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

Regards, Per