How to Fix Error 521 for Cloudflare and WordPress When that happens, Cloudflare won’t be able to connect and will display the Error 521 message instead. As such, some security solutions will view high traffic from a limited number of IP addresses as an attack and block them. Because of how Cloudflare works, some server-side security solutions might inadvertently block Cloudflare’s IP addresses.īecause Cloudflare is a reverse proxy, all of the traffic coming to your origin server will appear as if it’s coming from a small range of Cloudflare IPs ( rather than each individual visitor’s unique IP address). Second, your web server might be running fine but blocking Cloudflare’s requests for some reason. Even if everything else is configured properly, if your WordPress site’s server is offline, Cloudflare simply won’t be able to connect.
Typically, the Error 521 message is caused by one of two situations:įirst, your WordPress site’s server may be down. An example of the Error 521 message What Causes the Error 521 Message?
