How to Fix Remote Desktop Services 504 Gateway Timeout - Step-by-Step: Set Up PowerShell for Office 365 Migration-Configure Network for Windows Terminal Profiles
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.