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 VSCode Permission Denied in Docker Containers
When using Visual Studio Code's Remote – Containers extension or attaching to a running Docke...
How to Fix Git 'index.lock' File Exists Error
When you see fatal: Unable to create 'path/.git/index.lock': File exists., G...
Fix Windows Cannot Access Shared Folder: Network Path Not Found
You try to access a shared folder on another computer and get the error: 'Windows cannot acce...
Fix Nginx Configuration Test Failure from Rewrite Rules
You run nginx -t and get an error. The log points to a rewrite rule. This is common ...
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...
Topic paths
Quick titles
How to Fix Missing Env Variables in npm BuildTroubleshoot Firefox Malware Secure Connection FailedFix Docker Compose Volume Permission Denied ErrorsHow to Stop Chrome Access Violation CrashesFix Git Pull Unrelated Histories Error: Step-by-StepPython Requests Timeout: How to Raise ItDocker Desktop Engine Stopped on Mac M1: Fixes That WorkFix Windows 11 Error 0x80070005 (Access Denied)