Github login yields server error on main site

[Marwe]

If the naming of the error image [1] is correct a 500 (or maybe it stands for 5xx?) error code is returned after trying to log in with github OAUTH on gettogether.community. Redirect from provider back to main site seems not to work.

Is it a bug on the website that can be fixed?
Any chance to recover from that situation, if no other login options are active?

[1] https://gettogether.community/static/img/500.png

[Marwe]

This is the redirect page error:

HTTP/1.1 500 Internal Server Error
Date: Tue, 21 Sep 2021 23:01:14 GMT
Server: Apache/2.4.18 (Ubuntu)
Content-Language: de
Vary: Accept-Language,Cookie
X-Frame-Options: SAMEORIGIN
Set-Cookie: messages="SNIPPED$[[\"__json_message\"\0540\05440\054\"Authentication process canceled\"\054\"social-auth github\"]]"; HttpOnly; Path=/
Content-Length: 4401
Connection: close
Content-Type: text/html; charset=utf-8