I’ve been looking around and so far I haven’t found any information on whether or not mattermost can be installed on Debian Linux 9.
In my understanding it should work, we support Debian and different Linux versions: https://docs.mattermost.com/install/requirements.html?highlight=requirement#mattermost-server-operating-system.
Did you try with Debian Linux 9 and experience issues? If yes, we can help troubleshoot further.
I was having some issues, but I managed to at least get it running. I have a problem though, the very first time I accessed it and registered a user, it didn’t ask to create a team - hence it’s not in system_admin group. Manually adding users with cli to system_admins doesnt work either. Im running debian 9 with apache proxy.
Does a thread like this seem to describe the issue you are seeing: "No teams are available to join", how do I create one??