Fix BitLocker Cache Full Error on Windows 11 - Fix Windows Defender Real-Time Protection Turned Off & Connection Refused-Troubleshooting Cloudflare Error 521

Updated 2026-06-13 23:01:12security-tools
Fix BitLocker Cache Full Error on Windows 11 - Fix Windows Defender Real-Time Protection Turned Off & Connection Refused-Troubleshooting Cloudflare Error 521
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.