502 we had several times a few months ago. There were different constellations that caused this. But we should avoid them mostly by correcting the installation scripts. So I have to ask:
When did you try this?
When’s the installation date?
You should read this:
Wiki:
19.1 Installation using egroupware docker RPM DEB package
19.1 Release notes and distribution specific instructions
Update recommendations and troubleshooting
Forum:
My installation of EGroupware 19.1 on Debian 10
Docker (in EGroupware 19.1)?
And from here, of course:
EGroupware 19.1 Release Notes / Changelog
If you try it again and you find such a problem, create a new (!) topic here in the forum. Until then please mark this one as solved.
Stefan