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Fix Cloudflare 521 Error: DNS Configuration Problem - Nginx Syntax Error: Common Causes and Solutions-Fix Chrome Certificate Error: Invalid Authority with Proxy Settings

2026-07-28 16:43:50
Fix Cloudflare 521 Error: DNS Configuration Problem - Nginx Syntax Error: Common Causes and Solutions-Fix Chrome Certificate Error: Invalid Authority with Proxy Settings

Result check

  • Keep one change per test run so you know which step helped.
  • Undo temporary changes after the issue is confirmed.

Next references

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