LND will not start; issue with opening the graph database

[Koola-T]

My node crashed, so I rebooted the machine. After restarting, I was able to bring all services back online except LND. The relevant error in the LND log states “LTND: unable to open graph DB: ReadVarBytes; sig is larger than the max allowed size [count 179, max 80]”. I would appreciate any guidance on how to resolve this issue and get LND functioning again.

[guggero]

Sounds like the database suffered data corruption due to the unclean shutdown.
You can try chantools compactdb. If that succeeds without errors, you should be able to continue using the node.
If there are errors, you might need to do the emergency recovery procedure which unfortunately involves closing all channels.