A JavaScript Error Occurred in the Main Process Windows 11

If you see a message like “A JavaScript error occurred in the main process” when launching an app (often an Electron-based app like Discord, Slack, VS Code, or others), it means some part of the app’s background process had a failure. It could be due to corrupted files, a bad installation, conflicting versions, missing dependencies, or permissions issues. While the app might sometimes still run after you click “OK,” the error is annoying and often signals underlying problems that can lead to instability or features not working.

How to Fix the Error

Here are steps people have successfully used to resolve this error. Try them in order, or pick ones that match your symptoms.

1. Uninstall and Reinstall the App
   • Open Settings → Apps → Apps & features.
   • Find the problematic app, uninstall it.
   • After uninstall, ensure any leftover folders (in Program Files, AppData\Local, AppData\Roaming) are removed.
   • Download the latest version from the official site and install fresh.
   • Check if the error persists.
2. Run System File Checker (SFC) and DISM
   These are built-in Windows tools that repair corrupted system files.
   • Open Command Prompt as Administrator.
   • Run: sfc /scannow
   • After that finishes, run: DISM /Online /Cleanup-Image /RestoreHealth
   • Restart your PC and try the app again.
3. Use Autoruns to Diagnose Startup Items
   • Download Autoruns from Microsoft Sysinternals (or use the Live version).
   • Run it as admin.
   • Go to the Logon tab to see what apps run at startup.
   • Disable or remove startup items that may interfere (especially electron-based apps, or software known to conflict).
   • Reboot and test the app.
4. Check Startup Apps via Task Manager
   • Open Task Manager (Ctrl+Shift+Esc), go to Startup tab.
   • Identify apps with high impact or that are known to use Electron / JavaScript.
   • Disable them (right click → Disable).
   • Reboot and see if error disappears.
5. Check Network/Internet Connectivity for Apps That Need It
   Sometimes this error shows up if the app tries to access a service and times out (e.g. “ETIMEDOUT”).
   • Ensure you’re online, firewall or proxy settings aren’t blocking the app.
   • If the app was working before but not now, check if your network changed or VPN/proxy settings are interfering.
6. Run App as Administrator or Adjust Permissions
   • Right-click the app shortcut → Run as administrator.
   • If it works, adjust its properties so it always runs with elevated permissions.
   • Also check that its installation folder allows your user account to read/write.
7. Clear Cache / Config Files
   • Navigate to the app’s data / config directories (often in %AppData% or %LocalAppData%) and delete or rename them (so backups exist).
   • Relaunch the app so it recreates fresh config.
8. Check for Conflicting Software
   • Some apps (especially “helper” tools, overlays, or ones that inject code / UI) can conflict.
   • Temporarily disable antivirus, disable overlays, or close suspect apps and test again.