How to Fix '404 Not Found' in Command Prompt on Windows 10 - Fix Nginx 404 Not Found Caused by Missing Index File-Fix OneDrive Sync 504 Gateway Timeout Error
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.