Fix Nginx 502 Bad Gateway: Upstream Connection Refused
If you're seeing a 502 Bad Gateway error with "upstream connection refused" in your N...
Checklists for software errors, setup, and tool workflows.
1. Reproduce
2. Isolate
3. Apply
4. Verify
Latest checklists
View listCloudflare SSL Full Strict Error 525 Fixes
If you see Error 525: SSL handshake failed when using Cloudflare with SSL set to...
Fix Windows Security App Blocked by Antivirus
You open Windows Security (formerly Windows Defender) only to see an error or blank screen becaus...
Fix Nginx Configuration Test Failure in Docker
When you run nginx -t inside a Docker container and get an error, the container usua...
Fix Cloudflare SSL Full Strict Certificate Mismatch Error
If you set Cloudflare SSL/TLS encryption mode to Full (strict) and see a certificate mismatch err...
Fix Windows 11 Installation Assistant Stuck at 99%
Many users report that the Windows 11 Installation Assistant gets stuck at 99% during the upgrade...
Topic paths
Quick titles
Troubleshoot Error 0x80070035 When Accessing Network ShareStop Nginx Redirect Loop in Server BlockFix Edge Sync Permission Denied ErrorTroubleshooting Nginx Backend Connection RefusedExternal Monitor Black Screen in Chrome TroubleshootingWindows 11 Blue Screen After Update: Hardware TroubleshootingHow to Use nvm to Change Node Version per ProjectRemote Desktop Failed: Password Expired – Solutions