Fix 'Windows Defender Failed to Start Due to Group Policy' Error - Fix Windows 10 Activation Error 0x803fa067-Ubuntu APT Lock After Update: Quick Fix
Before changing system settings, save your work and note the exact error text so you can compare results after each step.
Extra verification checklist
- Restart the affected app after changing permissions or configuration files.
- Test the same workflow in a clean browser profile or a temporary user account.
- Compare the result on another network if the error may be connection related.