Windows Defender Service Not Working in Windows 11: Fixes - How to Get Windows Security Service Running Again-Windows Security 504 Error After Network Driver Update
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.