Web server is returning an unknown error 520

tiendungdev

I have installed Nginx and use Cloudflare proxy to run my WordPress website but I get this error if I click on preloading wp-rocket - https://prnt.sc/Oq7LLZGJtMRL

"Web server is returning an unknown error Error code 520" - https://prnt.sc/Vdk5A5dbV-aW

If I disable Cloudflare proxy preloading cache works properly

Has anyone encountered this error?

Thank you.

alilet

Check logs to have an idea what's going on.

Check nginx logs at:

/var/log/nginx

Check php-fpm logs at:

/var/log/php8.2-fpm.log

Replace 8.2 with your version number.

tiendungdev

Thank you.

There are no errors in 3 files

php-fpm.log
php8.1-fpm.log
error.log - nginx

hyena56

Have u tried disabling HTTP/2 Origin (can be found on Speed -> Optimization) on your Cloudflare, or temporarily disable HTTP/2 on NGINX configuration (if you have)

slimbro

try change your ssl setting in cloudflare to flexible

tiendungdev

@hyena56 said:
Have u tried disabling HTTP/2 Origin (can be found on Speed -> Optimization) on your Cloudflare, or temporarily disable HTTP/2 on NGINX configuration (if you have)

Thank you, problem solved.