Replied to the thread OMV 5.x resolved Upgrade 4.x -> 5.x No access to web interface after 4 to 5 upgrade.PostI had no access to webgui with user admin and the right password.
It says "Incorrect username or password".
Changing password with omv-firstaid didn't help.
Reset failed password count with omv-firstaid didn't help.
Root cause seems to be a missing group…