GitHub Copilot plugin update fails: AccessDeniedException on Windows

Problem

GitHub Copilot plugin update fails with AccessDeniedException on Windows. The IDE may report the plugin was updated, but on restart shows:

The IDE failed to install or update some plugins.
java.nio.file.AccessDeniedException: …\plugins\github-copilot-intellij\copilot-agent\bin\copilot-agent-win.exe

In newer plugin versions, the binary was renamed and the error references copilot-language-server.exe instead:

java.nio.file.AccessDeniedException: …\plugins\github-copilot-intellij\copilot-agent\bin\copilot-language-server.exe

The error persists on every subsequent update attempt.

Cause

The GitHub Copilot plugin runs a satellite process (copilot-agent-win.exe or copilot-language-server.exe) that may not terminate during IDE shutdown. The locked file prevents the IDE from replacing it with the updated version.

This is a known third-party issue tracked in GitHub community discussions:

• 17298 — original report
• 138963 — report with copilot-language-server.exe

There is currently no IDE API for plugins to register satellite processes for graceful shutdown termination (IJPL-148314).

Resolution

Option 1: Kill the stale process after a failed update

If the update already failed:

1. Close the IDE
2. Open Task Manager and terminate any copilot-agent-win.exe or copilot-language-server.exe process
3. Restart the IDE — it applies the pending update on launch

Option 2: Close the IDE instead of restarting

When the IDE prompts to restart after the update, do not click Restart. Instead:

1. Close the IDE completely via File | Exit
2. Reopen the IDE — it applies the pending update on launch

Option 3: Disable the plugin before updating

1. Open File | Settings | Plugins
2. Find GitHub Copilot and click Disable
3. Close the IDE completely
4. Verify no copilot-agent-win.exe or copilot-language-server.exe process is running in Task Manager
5. Start the IDE and update the plugin (if the plugin was disabled in step 2, the process will succeed)
6. Re-enable the plugin and restart