I just installed the app and after running it I only see this screen
The first time the IDE runs, it has to download many files. If you don't see any activity after 15 minutes, shut it down and restart it.
Hi @aqurgo. 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 -
(whereC:\Users\<username>\AppData\Local\Programs\Arduino IDE<username>is your Windows username)
If looking for it with your file manager or command line, note that the AppDatafolder 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.
- 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.
PowerShell 7.5.4
PS C:\Users\grapi\AppData\Local\Programs\arduino-ide> & ".\Arduino IDE"
PS C:\Users\grapi\AppData\Local\Programs\arduino-ide>
Arduino IDE 2.3.8
Checking for frontend application configuration customizations. Module path: C:\Users\grapi\AppData\Local\Programs\arduino-ide\resources\app\lib\backend\electron-main.js, destination 'package.json': C:\Users\grapi\AppData\Local\Programs\arduino-ide\resources\app\package.json
Setting 'theia.frontend.config.appVersion' application configuration value to: "2.3.8" (type of string)
Setting 'theia.frontend.config.cliVersion' application configuration value to: "1.4.1" (type of string)
Setting 'theia.frontend.config.buildDate' application configuration value to: "2026-02-25T15:38:21.789Z" (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}${appName}","files.autoSave":"afterDelay","editor.minimap.enabled":false,"editor.tabSize":2,"editor.scrollBeyondLastLine":false,"editor.quickSuggestions":{"other":false,"comments":false,"strings":false},"editor.maxTokenizationLineLength":500,"editor.bracketPairColorization.enabled":false,"breadcrumbs.enabled":false,"workbench.tree.renderIndentGuides":"none","explorer.compactFolders":false},"appVersion":"2.3.8","cliVersion":"1.4.1","buildDate":"2026-02-25T15:38:21.789Z"}
Starting backend process. PID: 22992
Showing main window early
Using browser-only version of superagent in non-browser environment
Configuration directory URI: 'file:///c%3A/Users/grapi/.arduinoIDE'
Configuring to accept webviews on '^.+\.webview\..+$' hostname.
2026-03-20T21:16:35.975Z root INFO Backend u.initialize: 31.2 ms [Finished 0.925 s after backend start]
2026-03-20T21:16:35.978Z root INFO Backend Object.initialize: 26.9 ms [Finished 0.925 s after backend start]
2026-03-20T21:16:35.978Z root INFO Backend a.initialize: 1.8 ms [Finished 0.925 s after backend start]
2026-03-20T21:16:35.978Z root INFO Backend a.initialize: 1.4 ms [Finished 0.925 s after backend start]
2026-03-20T21:16:35.978Z root INFO Backend u.initialize: 1.7 ms [Finished 0.926 s after backend start]
2026-03-20T21:16:35.981Z root INFO Backend l.initialize: 28.3 ms [Finished 0.927 s after backend start]
2026-03-20T21:16:35.988Z root INFO configured all backend app contributions
2026-03-20T21:16:35.989Z root INFO Backend l.onStart: 1.5 ms [Finished 0.940 s after backend start]
2026-03-20T21:16:35.990Z root INFO Backend d.onStart: 0.2 ms [Finished 0.941 s after backend start]
2026-03-20T21:16:35.990Z root INFO Backend a.onStart: 0.4 ms [Finished 0.941 s after backend start]
2026-03-20T21:16:35.991Z config INFO >>> Initializing CLI configuration...
2026-03-20T21:16:35.991Z root INFO Backend x.onStart: 0.5 ms [Finished 0.942 s after backend start]
2026-03-20T21:16:35.991Z config INFO Loading CLI configuration from c:\Users\grapi\.arduinoIDE\arduino-cli.yaml...
2026-03-20T21:16:35.991Z daemon INFO Starting daemon from C:\Users\grapi\AppData\Local\Programs\arduino-ide\resources\app\lib\backend\resources\arduino-cli.exe...
2026-03-20T21:16:35.991Z root INFO Backend w.onStart: 0.4 ms [Finished 0.942 s after backend start]
2026-03-20T21:16:35.991Z discovery-log INFO start
2026-03-20T21:16:35.991Z discovery-log INFO start new deferred
2026-03-20T21:16:35.991Z root INFO Backend v.onStart: 0.3 ms [Finished 0.943 s after backend start]
2026-03-20T21:16:35.991Z root INFO Backend a.onStart: 0.1 ms [Finished 0.943 s after backend start]
2026-03-20T21:16:35.999Z root INFO Theia app listening on http://127.0.0.1:50693.
2026-03-20T21:16:35.999Z root INFO Finished starting backend application: 7.8 ms [Finished 0.951 s after backend start]
2026-03-20T21:16:36.141Z root WARN The local plugin referenced by local-dir:/c%3A/Users/grapi/.arduinoIDE/plugins does not exist.
2026-03-20T21:16:36.141Z root WARN The local plugin referenced by local-dir:/c%3A/Users/grapi/.arduinoIDE/deployedPlugins does not exist.
2026-03-20T21:16:36.141Z root WARN The local plugin referenced by local-dir:C:\Users\grapi\.arduinoIDE\plugins does not exist.
2026-03-20T21:16:36.170Z config INFO Loaded CLI configuration: {"board_manager":{"additional_urls":[]}}
2026-03-20T21:16:36.170Z config INFO Loading fallback CLI configuration to get 'directories.data' and 'directories.user'
2026-03-20T21:16:36.313Z daemon INFO time="2026-03-20T17:16:36-04:00" level=info msg="arduino-cli version 1.4.1"
2026-03-20T21:16:36.317Z daemon INFO time="2026-03-20T17:16:36-04:00" level=info msg="Using config file: c:\\Users\\grapi\\.arduinoIDE\\arduino-cli.yaml"
time="2026-03-20T17:16:36-04:00" level=info msg="Executing `arduino-cli daemon`"
2026-03-20T21:16:36.332Z daemon INFO Daemon is now listening on 127.0.0.1:50694
{"IP":"127.0.0.1","Port":"50694"}
2026-03-20T21:16:36.332Z daemon INFO Daemon is running.
2026-03-20T21:16:36.339Z config INFO Loaded fallback CLI configuration: {"directories":{"user":"C:\\Users\\grapi\\Documents\\Arduino","data":"C:\\Users\\grapi\\AppData\\Local\\Arduino15"}}
2026-03-20T21:16:36.340Z config INFO Merged CLI configuration with the fallback: {"directories":{"user":"C:\\Users\\grapi\\Documents\\Arduino","data":"C:\\Users\\grapi\\AppData\\Local\\Arduino15"},"board_manager":{"additional_urls":[]}}
2026-03-20T21:16:36.340Z config INFO Loaded the CLI configuration.
2026-03-20T21:16:36.351Z config INFO Mapped the CLI configuration: {"dataDirUri":"file:///c%3A/Users/grapi/AppData/Local/Arduino15","sketchDirUri":"file:///c%3A/Users/grapi/Documents/Arduino","additionalUrls":[],"network":"none","locale":"en"}
2026-03-20T21:16:36.351Z config INFO Validating the CLI configuration...
2026-03-20T21:16:36.357Z config INFO The CLI config is valid.
2026-03-20T21:16:36.357Z config INFO <<< Initialized the CLI configuration.
2026-03-20T21:16:36.360Z daemon INFO time="2026-03-20T17:16:36-04:00" level=info msg="Starting download" url="https://downloads.arduino.cc/libraries/library_index.tar.bz2"
2026-03-20T21:16:36.374Z root INFO Resolve plugins list: 381.1 ms [Finished 1.326 s after backend start]
2026-03-20T21:16:37.663Z root INFO creating connection for 1
2026-03-20T21:16:39.123Z root WARN Frontend a.configure took longer than the expected maximum 100 milliseconds: 249.1 ms [Finished 3.049 s after frontend start]
2026-03-20T21:16:39.167Z 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'.
2026-03-20T21:16:39.328Z root WARN Frontend keybindings.onStart took longer than the expected maximum 100 milliseconds: 161.5 ms [Finished 3.244 s after frontend start]
2026-03-20T21:16:39.425Z root INFO Start frontend contributions: 645.8 ms [Finished 3.330 s after frontend start]
2026-03-20T21:16:39.425Z root INFO Changed application state from 'init' to 'started_contributions'.
2026-03-20T21:16:39.449Z root INFO Changed application state from 'started_contributions' to 'attached_shell'.
2026-03-20T21:16:39.449Z root INFO >>> Restoring the layout state...
2026-03-20T21:16:41.845Z root INFO Deploy plugins list: 5851.3 ms [Finished 6.796 s after backend start]
2026-03-20T21:16:41.854Z root INFO [8a85cafa-6735-4ee2-838d-e0789b1d31c5] Waiting for backend deployment: 2455.1 ms [Finished 5.777 s after frontend start]
2026-03-20T21:16:42.082Z 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?
2026-03-20T21:16:42.082Z 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\grapi\AppData\Local\Arduino15\library_index.json: The system cannot find the file specified.
2026-03-20T21:16:42.087Z 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\grapi\AppData\Local\Arduino15\library_index.json: The system cannot find the file specified.
2026-03-20T21:16:42.088Z daemon INFO time="2026-03-20T17:16:41-04:00" level=info msg="Checking signature" index="C:\\Users\\grapi\\AppData\\Local\\Arduino15\\package_index.json" signatureFile="C:\\Users\\grapi\\AppData\\Local\\Arduino15\\package_index.json.sig" trusted=true
time="2026-03-20T17:16:41-04:00" level=info msg="Loading hardware from: C:\\Users\\grapi\\AppData\\Local\\Arduino15\\packages"
time="2026-03-20T17:16:41-04:00" level=info msg="Loading package builtin from: C:\\Users\\grapi\\AppData\\Local\\Arduino15\\packages\\builtin"
time="2026-03-20T17:16:41-04:00" level=info msg="Checking existence of 'tools' path: C:\\Users\\grapi\\AppData\\Local\\Arduino15\\packages\\builtin\\tools"
time="2026-03-20T17:16:41-04:00" level=info msg="Loading tools from dir: C:\\Users\\grapi\\AppData\\Local\\Arduino15\\packages\\builtin\\tools"
time="2026-03-20T17:16:41-04:00" level=info msg="Loaded tool" tool="builtin:ctags@5.8-arduino11"
time="2026-03-20T17:16:41-04:00" level=info msg="Loaded tool" tool="builtin:dfu-discovery@0.1.2"
time="2026-03-20T17:16:41-04:00" level=info msg="Loaded tool" tool="builtin:mdns-discovery@1.0.12"
time="2026-03-20T17:16:41-04:00" level=info msg="Loaded tool" tool="builtin:serial-discovery@1.4.3"
time="2026-03-20T17:16:41-04:00" level=info msg="Loaded tool" tool="builtin:serial-monitor@0.15.0"
time="2026-03-20T17:16:42-04:00" level=info msg="Loading libraries index file" index="C:\\Users\\grapi\\AppData\\Local\\Arduino15\\library_index.json"
time="2026-03-20T17:16:42-04:00" level=info msg="Adding libraries dir" dir="C:\\Users\\grapi\\AppData\\Local\\Arduino15\\libraries" isSingleLibrary=false location=ide
time="2026-03-20T17:16:42-04:00" level=info msg="Adding libraries dir" dir="C:\\Users\\grapi\\Documents\\Arduino\\libraries" isSingleLibrary=false location=user
2026-03-20T21:16:42.593Z daemon INFO time="2026-03-20T17:16:42-04:00" level=info msg="Starting download" url="https://downloads.arduino.cc/libraries/library_index.tar.bz2"
2026-03-20T21:16:42.595Z root INFO core-client-provider [library-index] Downloading index: library_index.tar.bz2
2026-03-20T21:16:42.596Z root INFO [hosted-plugin: 2120] PLUGIN_HOST(2120) starting instance
[Object: null prototype] {}
2026-03-20T21:16:43.379Z root INFO [8a85cafa-6735-4ee2-838d-e0789b1d31c5] Sync of 23 plugins: 1530.8 ms [Finished 7.308 s after frontend start]
2026-03-20T21:16:45.322Z daemon INFO time="2026-03-20T17:16:45-04:00" level=info msg="Starting download" url="https://downloads.arduino.cc/libraries/library_index.tar.bz2"
2026-03-20T21:16:48.374Z 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?
2026-03-20T21:16:48.390Z daemon INFO time="2026-03-20T17:16:48-04:00" level=info msg="Checking signature" index="C:\\Users\\grapi\\AppData\\Local\\Arduino15\\package_index.json" signatureFile="C:\\Users\\grapi\\AppData\\Local\\Arduino15\\package_index.json.sig" trusted=true
2026-03-20T21:16:48.392Z daemon INFO time="2026-03-20T17:16:48-04:00" level=info msg="Loading hardware from: C:\\Users\\grapi\\AppData\\Local\\Arduino15\\packages"
2026-03-20T21:16:48.393Z daemon INFO time="2026-03-20T17:16:48-04:00" level=info msg="Loading package builtin from: C:\\Users\\grapi\\AppData\\Local\\Arduino15\\packages\\builtin"
2026-03-20T21:16:48.393Z daemon INFO time="2026-03-20T17:16:48-04:00" level=info msg="Checking existence of 'tools' path: C:\\Users\\grapi\\AppData\\Local\\Arduino15\\packages\\builtin\\tools"
time="2026-03-20T17:16:48-04:00" level=info msg="Loading tools from dir: C:\\Users\\grapi\\AppData\\Local\\Arduino15\\packages\\builtin\\tools"
2026-03-20T21:16:48.395Z daemon INFO time="2026-03-20T17:16:48-04:00" level=info msg="Loaded tool" tool="builtin:ctags@5.8-arduino11"
2026-03-20T21:16:48.395Z daemon INFO time="2026-03-20T17:16:48-04:00" level=info msg="Loaded tool" tool="builtin:dfu-discovery@0.1.2"
2026-03-20T21:16:48.396Z daemon INFO time="2026-03-20T17:16:48-04:00" level=info msg="Loaded tool" tool="builtin:mdns-discovery@1.0.12"
2026-03-20T21:16:48.396Z daemon INFO time="2026-03-20T17:16:48-04:00" level=info msg="Loaded tool" tool="builtin:serial-discovery@1.4.3"
2026-03-20T21:16:48.396Z daemon INFO time="2026-03-20T17:16:48-04:00" level=info msg="Loaded tool" tool="builtin:serial-monitor@0.15.0"
2026-03-20T21:16:48.418Z daemon INFO time="2026-03-20T17:16:48-04:00" level=info msg="Loading libraries index file" index="C:\\Users\\grapi\\AppData\\Local\\Arduino15\\library_index.json"
2026-03-20T21:16:48.419Z 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\grapi\AppData\Local\Arduino15\library_index.json: The system cannot find the file specified.
2026-03-20T21:16:48.419Z daemon INFO time="2026-03-20T17:16:48-04:00" level=info msg="Adding libraries dir" dir="C:\\Users\\grapi\\AppData\\Local\\Arduino15\\libraries" isSingleLibrary=false location=ide
time="2026-03-20T17:16:48-04:00" level=info msg="Adding libraries dir" dir="C:\\Users\\grapi\\Documents\\Arduino\\libraries" isSingleLibrary=false location=user
2026-03-20T21:16:48.420Z 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\grapi\AppData\Local\Arduino15\library_index.json: The system cannot find the file specified.
2026-03-20T21:16:48.421Z 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\grapi\AppData\Local\Arduino15\library_index.json: The system cannot find the file specified.
at C:\Users\grapi\AppData\Local\Programs\arduino-ide\resources\app\lib\backend\main.js:2:6323812
at y.evaluateErrorStatus (C:\Users\grapi\AppData\Local\Programs\arduino-ide\resources\app\lib\backend\main.js:2:6323828)
at process.processTicksAndRejections (node:internal/process/task_queues:95:5)
at async a.<anonymous> (C:\Users\grapi\AppData\Local\Programs\arduino-ide\resources\app\lib\backend\main.js:2:6323498)
type or paste code here
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:
- Right click the Windows Start icon (⊞) on the taskbar.
A context menu will open. - Select "Settings" from the context menu.
Windows "Settings" will open. - Select "Time & language" from the navigation panel on the left side of the window.
- Select "Date & time" from the list at the right side of the Settings window.
The "Date & time" settings section will expand. - Click the "Sync now" button that is located under the "Additional settings" section of the window.
- Wait for the syncing process to finish.
- Close any Arduino IDE windows that are open.
- 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.
Thank you for helping me it works now
You are welcome. I'm glad it is working now.
Regards, Per