I think ubuntu also uses journalctl so heres a command I took from another topic to view system logs if theres some hints why OH won’t start.
journalctl -u openhab2.service -b
-u openhab2.service is to show only log entries made by OH and -b is to show only entries after last boot.
Here’s the link to the topic I picked the command from. [SOLVED] Openhab2 not starting after apt-get update = solved - #3 by Benjy