Fixing Cloudflare 521 Error: Origin Unreachable
When you see Cloudflare error 521, it means your origin server is refusing the connection from Cl...
Checklists for software errors, setup, and tool workflows.
1. Reproduce
2. Isolate
3. Apply
4. Verify
Latest checklists
View listCloudflare SSL Full Strict Not Working After Update: Fixes
After a Cloudflare update or configuration change, you might see SSL errors like ERR_SSL_PR...
Fix Windows Remote Desktop Not Connecting After Sleep
After your computer wakes from sleep or hibernation, Remote Desktop may refuse to connect. This i...
Fixing Nginx Upstream Connection Refused on Port 443
You see "upstream connection refused" in your Nginx error log when proxying requests to p...
Checklist for Fixing Shared Folder Access in Windows
When you can't access a shared folder on Windows, the problem usually comes down to permissio...
Fix Git Clone Connection Timed Out Due to Proxy Settings
You run git clone https://github.com/example/repo.git and after a long pause you get...
Topic paths
Quick titles
Windows Can't Access Shared Folder? Firewall FixFix Cloudflare Full Strict Self-Signed Certificate ErrorResolve Node Sass Binding Not FoundFix Windows Update Error 0x800f081f with System File CheckerDocker Container Exits Immediately on Mac: FixesWindows 11 Bluetooth Driver Fix GuideTroubleshoot Cloudflare 521 and Proxy IssuesSwitching from Cloudflare Origin Certificate to Let's Encrypt