Fix Windows Security App Not Starting on Windows 11
You click the Windows Security icon or try to open it from Settings, but nothing happens. The app...
Checklists for software errors, setup, and tool workflows.
1. Reproduce
2. Isolate
3. Apply
4. Verify
Latest checklists
View listWindows Defender Real-Time Protection Troubleshooting Checklist
If Windows Defender real-time protection fails to turn on or keeps turning off, you may see warni...
Remote Desktop Connection Fails: RDP Port Not Open
You try to connect via Remote Desktop, but the client says it can't connect. One of the most ...
Cloudflare 521 Error: How to Check Server Logs
If you're seeing a Cloudflare 521 error, it means Cloudflare tried to connect to your origin ...
Fix ERR_CERT_AUTHORITY_INVALID in Chrome Incognito Mode
You open Chrome incognito and hit a warning: NET::ERR_CERT_AUTHORITY_INVALID. Th...
How to Fix Nginx 502 Bad Gateway in Docker
If you're running Nginx as a reverse proxy inside Docker and seeing a 502 Bad Gateway error, ...
Topic paths
Quick titles
Windows Update Error 0x80070002: Network Troubleshooting GuideWhy Your VSCode Breakpoints Are Not WorkingHow to Fix Git SSL Certificate Verify Failed ErrorDealing with pip's Externally Managed EnvironmentFix Remote Desktop Certificate Errors in WindowsChrome Print Error Access Violation GuideChrome Update Causing Black Screen? Disable Hardware AccelerationGit Detached HEAD Warning: What It Means and How to Fix It