Tag

#Error 521

1 article

Chronicle

1 posts

2026

01
  1. 01 How to Fix Cloudflare Error 521: Don't Clear the Cache, Trace the Path Cloudflare Error 521 (Web server is down) isn't fixed by clearing the cache — it means your origin refused Cloudflare's connection. This guide walks the path from web service and listening ports through firewalls / WAF and SSL/TLS ports to load balancers, plus a ready-to-send support ticket template.