How to Fix Cloudflare 521 Error Due to Proxy Issues
If you see a Cloudflare 521 error, the message usually says something like “Web server is down.” ...
Software troubleshooting desk
Practical fixes for tool errors, setup blocks, and workflow issues.
Symptom
Cause
Fix route
Verify
Fresh repair notes
All notesNginx Upstream Connection Refused: Fixing localhost Errors
You set up an nginx reverse proxy to forward requests to a backend service on localhost, but ngin...
Fix Git index.lock File Exists Permission Denied Error
You're in the middle of a Git operation and suddenly you see:
fatal: Unable to ...How to Fix Git 'index.lock' File Exists Error
When you see fatal: Unable to create 'path/.git/index.lock': File exists., G...
Docker Desktop Engine Stopped on Mac M1: Fixes That Work
On Apple Silicon Macs (M1, M2, M3), Docker Desktop sometimes shows the error “Docker Desktop engi...
Repair Corrupt Windows Search Index Database
When Windows Search stops returning files or emails, or the search box hangs, a corrupt index dat...
Issue queue
SitemapDiagnosing Chrome Invalid Authority Certificate Errors
Fixing 'Permission Denied' in Windows VSCode Terminal
Mac Chrome Extensions Not Loading – Troubleshooting Steps
Install Python Packages Without Sudo
Cloudflare Origin Certificate Invalid Error Fix
Windows Explorer Keeps Restarting After Software Install – Fix
How to Resolve 'Permission Denied' in VS Code Python Terminal
How to Fix DNS Probe Finished NXDOMAIN on Windows 10
How to Fix Chrome Startup Crash by Disabling Extensions
How to Fix node-sass Build Failed Error
Windows 11 WiFi No Internet – Proxy Fix
Fix Python Requests Timeout Not Waiting Correctly
Fixing 'Permission Denied' in Windows VSCode Terminal
Mac Chrome Extensions Not Loading – Troubleshooting Steps
Install Python Packages Without Sudo
Cloudflare Origin Certificate Invalid Error Fix
Windows Explorer Keeps Restarting After Software Install – Fix
How to Resolve 'Permission Denied' in VS Code Python Terminal
How to Fix DNS Probe Finished NXDOMAIN on Windows 10
How to Fix Chrome Startup Crash by Disabling Extensions
How to Fix node-sass Build Failed Error
Windows 11 WiFi No Internet – Proxy Fix
Fix Python Requests Timeout Not Waiting Correctly