Fix 'nginx: configuration test failed unexpected end of file' - Windows Update Service Not Listed in Services.msc-Resolve Cloudflare 521 Error on Apache
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.