Fix Windows Defender Not Starting Due to Dependency Conflict - Fix Windows Security Center Version Mismatch Errors-Windows 11 Windows Defender White Screen Solution
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.