Our server is deadlocking randomly. I have absolutely no idea what's causing this. It's happened about 7 times, always the same error.

We added Silent Gear and Botania, but these are pretty big mods and I know they're used together in packs all the time, so I wouldn't expect there to be an issue...

I couldn't find any rules on whether you're willing to offer support to players that have mods added, so if you don't, my apologies, but I thought I would try my luck. Thank you!

crash-2022-01-02_22.25.24-server.txt

It appears like you are having server lag, so a temporary stopgap would be:
In the server.properties file change the value of max-tick-time to -1

That should let you at least start the server again, but isn't a permanent fix for if you are having lag when it does start.

I'm also having this deadlock issue, with or without optifine, regardless of the number of players online. We'll play fine for an hour and then have a 13 second stall where the server doesn't respond.
What kind of information can I provide to help diagnose?