How to Fix Cloudflare 521 Error (Port 443 Blocked) - Fix Limited Connectivity on Windows 11 Wi-Fi: Practical Steps-Windows 11 Blue Screen Driver Update Rollback Guide
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.