Issue Roudcube + Cloudflare returns Error 520

[Ejindar]

Hello
webmail.domain.com. returns error 520
I guess Problem is from apache. i get same errors when i am trying to use Apache FPM and cloudflare give Error 520
In log files cant seee anything...
ssl settings are ok!
Reinstalled roundcube and horde
Repaired plesk
but no luck...

Any idea?

 

[Marcio Nunes]

Same problem here.
Enable http2 and error 520 cloudflare.

 

[robinrm]

i know it's in German but ovrall it's an very good instruction how to fix error 520 with Cloudflare Wie man Cloudflare's "Error 520" behebt: Web Server meldet einen unbekannten Fehler"

 

[Marcio Nunes]

I just add
proxy_hide_header Upgrade; in Additional nginx directives and work