Fix Cloudflare 521 Error Due to Server Overload
You see a Cloudflare 521 error page. The message says the web server is down. Often, this means y...
Checklists for software errors, setup, and tool workflows.
1. Reproduce
2. Isolate
3. Apply
4. Verify
Latest checklists
View listHow to Fix Git SSL Certificate Problem: Unable to Get Local Issuer
When you run a Git command and see error: SSL certificate problem: unable to get local issu...
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...
How to Fix Cloudflare 522 Error: Step-by-Step Support Guide
When you see a Cloudflare 522 error, it means the connection between Cloudflare and your origin s...
Nginx Upstream Connection Refused: Diagnosis and Fixes
When Nginx returns a 502 Bad Gateway or logs "upstream connection refused", it means Ngin...
How to Fix Cloudflare 522 Error (Firewall Blocking)
If you see a Cloudflare 522 error, the connection between Cloudflare and your origin server timed...
Topic paths
Quick titles
Fix Windows Update Error 0x800f081f Missing FilesFix Chrome ERR_CONNECTION_RESET Due to Proxy SettingsHow to Resolve pip Permission Denied on Linux/macOS/WindowsBreaking the Blue Screen Cycle After Windows 11 UpdateHow to Fix Chrome Access Violation on MacTroubleshoot Docker Desktop Startup Permission DeniedResolve Git index.lock Error on WindowsHow to Fix pnpm Install Stuck at Resolving Dependencies