[Observium] HTTP/1.0 500 after upgrading to latest version 12324

Hello,

We have just upgraded our subscription edition to the latest 12324 (from a pretty old version).

But the GUI is not accessible anymore afterwards, with HTTP/1.0 500 errors.

Restarting ‘httpd’ (showing ‘active (running)’) and reboot the server doesn’t help.

Any suggestions how we can fix it or troubleshoot further?

Thanks.

- Gordon