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 Error 0x80070005 in Windows 10 Update
When you try to install a Windows 10 update, you may see error 0x80070005 with a...
Fixing 'git rebase index.lock file exists' Error
When running git rebase, you may see an error like fatal: Unable to create ...
Fix Cloudflare SSL Full Strict Error 526
If you see error 526 in your browser when using Cloudflare with SSL set to Full (Strict), it mean...
How to Fix Nginx Upstream Connection Refused on Port 80
When nginx logs show "upstream connection refused" while connecting to port 80, it means ...
DNS Probe Finished NXDOMAIN: Troubleshooting Checklist
Seeing "DNS_PROBE_FINISHED_NXDOMAIN" in Chrome means the browser couldn't find the IP...
Topic paths
Quick titles
How to Fix Python Not Found in Git Bash on WindowsPython Dependency Conflict Troubleshooting GuideFix Chrome Sync After Cache ClearWindows 11 Network Reset No Internet FixHow to Enable Greyed Out Defender Real-Time ProtectionHow to Fix Chrome Startup Crash (No Error Message)Troubleshooting Git Rejected Non Fast ForwardResolve DNS Probe Finished NXDOMAIN Error in macOS