Try disabling the custom plugins and see if it helps.
NodeBB on Uberspace
as the topic title states I am trying to run a NodeBB forum on the shared hoster Uberspace. I am following the fairly recent guide from Til Zöller. It works fine until I change the user registration to "Admin Invite". Once a user tries to register he gets a registration error with the message
<!DOCTYPE HTML PUBLIC "-//IETF//DTD HTML 2.0//EN"> <html><head> <title>502 Proxy Error</title> </head><body> <h1>Proxy Error</h1> <p>The proxy server received an invalid
response from an upstream server.<br />
The proxy server could not handle the request <em><a href="/register">POST /register</a></em>.<p> Reason: <strong>Error reading from remote server</strong></p></p> <hr> <address>Apache/2.2.15 (CentOS) Server at xxx.xxx.uberspace.de Port 80</address> </body></html>
Any help would be highly appreciated.