Checklists for software errors, setup, and tool workflows.

How to Fix Git Push Rejected Non-Fast-Forward Error

When you run git push and see “rejected – non-fast-forward”, it means your local bra...

Fix Docker Nginx 502 Bad Gateway Upstream Error

When running Nginx as a reverse proxy in Docker, a 502 Bad Gateway error with 'upstream' ...

Fix Git 'index.lock file exists' Error

If you see fatal: Unable to create 'path/.git/index.lock': File exists. when...

Fix Windows Update Service Not Running Due to Group Policy

If Windows Update shows the service is not running and you suspect Group Policy, the problem is o...

Fix Nginx Upstream Connection Refused Error

When Nginx returns upstream connection refused in your error logs, it means Nginx tr...

Fix Git SSL Certificate Error: Unable to Get Local Issuer Certificate

When cloning or pulling from a Git repository, you may see:

fatal: unable to access...