Fix Windows Update 404 Not Found Error: Practical Steps - Remote Desktop Black Screen Step-by-Step Guide-How to Fix 'Clear Windows Security Cache Permission Denied'
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.