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Fix Cloudflare 521 Error: SSL Configuration Steps - How to Set Up Wildcard Subdomains in Cloudflare DNS-Troubleshoot Chrome Flickering and Black Screen

Updated 2026-07-28 14:28:40macos-help

Fix Cloudflare 521 Error: SSL Configuration Steps - How to Set Up Wildcard Subdomains in Cloudflare DNS-Troubleshoot Chrome Flickering and Black Screen

Prepare

Execute

Validate

Document

Operational follow-up

Record the exact option, command, or setting that changed the result.
Keep a rollback note if the workflow affects shared files or team settings.

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