Checklists for software errors, setup, and tool workflows.

1. Reproduce

2. Isolate

3. Apply

4. Verify

Latest checklists

You're in the middle of a Git operation—commit, merge, or rebase—and Git stops with: fa...

Fixing Nginx Upstream Connection Refused on Port 443
You see "upstream connection refused" in your Nginx error log when proxying requests to p...

Why npm Says 'package.json Not Found' and How to Fix It
You run npm install or npm start and get npm ERR! package.json no...

Fix Cloudflare Wildcard Subdomain Page Rule Not Working
You set up a wildcard subdomain page rule in Cloudflare—like * .example.com/*—but it...

Fix Windows Explorer Restarting with SFC Scannow
If Windows Explorer keeps restarting on its own—your taskbar disappears and reappears, or File Ex...

Fix npm install Incompatible Node Version Errors
When you run npm install and get an error about an incompatible Node.js version, it ...