Checklists for software errors, setup, and tool workflows.

1. Reproduce

2. Isolate

3. Apply

4. Verify

Latest checklists

If you see an error like fatal: Unable to create 'project/.git/index.lock': File ex...

Fix npm 'package.json not found' Error in Subdirectories
You're working in a subdirectory of your project, run npm install or npm r...

How to Fix Git 'index.lock' File Exists Error
When you see fatal: Unable to create 'path/.git/index.lock': File exists., G...

Fix Nginx Upstream Connection Refused & Upstream Not Found
When you see upstream connection refused or upstream not found in your ...

Cloudflare Wildcard Subdomain Cache Not Working: Fixes
If you use a wildcard DNS record like *.example.com proxied through Cloudflare, you ...

Increase Git Timeout for Large Repositories
When cloning or fetching a large repository, Git may time out before the transfer completes. This...