Fix Blue Screen After Windows 11 Feature Update - Troubleshooting Cloudflare 521 Error: Port 443 Blocked-Node.js Heap Out of Memory on Windows: How to Fix

Updated 2026-07-28 08:57:41browser-issues
Fix Blue Screen After Windows 11 Feature Update - Troubleshooting Cloudflare 521 Error: Port 443 Blocked-Node.js Heap Out of Memory on Windows: How to Fix
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.