Fix OneDrive Sync Setup Connection Refused Error - How to Fix 504 Gateway Timeout in Windows Search-How to Resolve BitLocker 504 Recovery Key Issue
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.