Fix Nginx Upstream Connection Refused in Proxy Pass
When Nginx returns a 502 Bad Gateway or logs upstream connection refused
Checklists for software errors, setup, and tool workflows.
1. Reproduce
2. Isolate
3. Apply
4. Verify
Latest checklists
View listFixing Cloudflare 521 Error: Enable Origin Pull Setup
If you see a Cloudflare 521 error, it means Cloudflare can't connect to your origin server. O...
How to Fix Nginx Redirect Loop Infinite Redirect
If you see a browser error like "ERR_TOO_MANY_REDIRECTS" or "redirect loop", Ngin...
Windows 11 Update Stuck at 0%: How to Fix
You start a Windows Update, and the progress bar sits at 0% for ten minutes, an hour, or longer. ...
Chrome Sync Not Working After Disabling Extensions: Fixes
You disabled some Chrome extensions to troubleshoot a problem, and now sync has stopped working –...
Python Virtual Environment Activation Failed: Common Fixes
You've created a Python virtual environment, but when you try to activate it, nothing happens...
Topic paths
Quick titles
Windows Update 0x80070002 After Update: FixesWindows 11 Blue Screen After Update: Hardware Issue FixesHow to Resolve Error 0x800f081f Using DISMPython venv Activation Failed: Troubleshooting GuideHow to Merge Unrelated Git Histories SafelyDocker Container Stops Immediately: Exit Code 0Fix 'Port Already Used by Another Container' in Docker ComposeGit SSL Certificate Problem: Unable to Get Local Issuer Fix