How to Fix Cloudflare 521 Error with Firewall Settings
If you see a 521 Web Server Is Down error when visiting your site through Cloudf...
Checklists for software errors, setup, and tool workflows.
1. Reproduce
2. Isolate
3. Apply
4. Verify
Latest checklists
View listFix Windows Update Service Stuck on Stopping
You try to stop the Windows Update service to troubleshoot an update issue, but it hangs on "...
Fix VSCode Git Authentication Failed on Windows
If you see "Authentication failed" when pushing or pulling in Visual Studio Code on Windo...
How to Fix Nginx Configuration Test Failed Error
When you run nginx -t and see "test failed", it means nginx found a problem ...
Fix Docker Volume Permission Denied for Nginx
When running Nginx in a Docker container with a bind-mounted volume for static files, you might s...
Fix Edge Sync Not Working Due to Third-Party Antivirus
If your Microsoft Edge browser stops syncing bookmarks, passwords, or settings after installing o...
Topic paths
Quick titles
Fix Windows Cannot Access Shared Folder with Password Protected SharingTroubleshooting Nginx 502 in Docker Multi-Container Environmentsnpm Build Failed on Mac: Troubleshooting GuideFix npm Permission Denied by Changing Global DirectoryHow to Fix Git Merge Unrelated Histories Errornpm ENOENT package.json Not Found FixFix Cloudflare 522 Error Firewall BlockingFix Windows Defender Real-Time Protection Disabled by Malware