How to Fix Cloudflare 521 Error with Firewall Settings - VS Code Save Error: Permission Denied Fix-How to Remove index.lock in SourceTree

Updated 2026-07-28 11:14:24developer-tools
How to Fix Cloudflare 521 Error with Firewall Settings - VS Code Save Error: Permission Denied Fix-How to Remove index.lock in SourceTree
Before changing system settings, save your work and note the exact error text so you can compare results after each step.

Extra verification checklist

  • Restart the affected app after changing permissions or configuration files.
  • Test the same workflow in a clean browser profile or a temporary user account.
  • Compare the result on another network if the error may be connection related.