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I changed my VM instance from "F1-micro" to "E2-micro". When I then restarted my machine, I couldn’t access my webpage using the domain name, the webpage just shows an "Error 521" code – showing that my browser is working, CDN is working but the host has an erorr. When I paste the VMs IP address into my webpage, however, it show’s the "Apache2 Debian Default Page".
Can somebody please help me with this?
2
Answers
Turns out this problem was caused by my having installed the Debian Apache server package and it is causing collisions between it and the Apache shipped in the stack. Bitnami Stacks are completely self-contained and run independently of the rest of the software or libraries installed on your system.
So to fix this, all I had to do was run the following commands:
The Error 521 message is caused by one of two situations:
First, check whether your WordPress site’s server is down. Even if everything else is configured properly, if your WordPress site’s server is offline, Cloudflare simply won’t be able to connect.
Second, your web server might be running fine but blocking Cloudflare’s requests. Because of how Cloudflare works, some server-side security solutions might inadvertently block Cloudflare’s IP addresses.
Cloudflare is a reverse proxy, all 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). Because of that, some security solutions will view high traffic from a limited number of IP addresses as an attack and block them.
Please check this link out in order to fix error 521 for Cloudflare and WordPress.