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 listFix VS Code Permission Denied Error Code 13
You open a file or run a task in VS Code and see Error: EACCES: permission denied, open ...
Fix Docker Pull Access Denied Due to Token Expiration
You try to pull an image from a private registry and get access denied or toke...
Fix Git SSL Certificate Problem: Unable to Get Local Issuer
When you run git clone or git pull and see an error like "S...
How to Fix Git Authentication Failed in VS Code
You're in VS Code, push or pull fails with "Authentication failed"—this is common and...
How to Fix Cloudflare Error 521: Server Not Responding
Cloudflare error 521 appears when your origin server refuses the connection from Cloudflare's...
Topic paths
Quick titles
Fix Nginx Configuration Test Failed on UbuntuDocker Image Build Fails with Context CanceledFix Nginx 'Permission Denied' Upstream ErrorsTroubleshooting Docker No Space Left on Device (Devicemapper)Fix Nginx Upstream Connection Refused in DockerCloudflare SSL Full Strict Troubleshooting StepsHow to Resolve ERR_CERT_AUTHORITY_INVALID in Chrome IncognitoGit Large File Push Timeout Troubleshooting