So I was using sponge for my Forge 1.12.2 server when it decided to crash my server every-time it loaded a new chunk when going long distances or if standing still.
Versions:
Sponge 1.12.2-2768-7.1.6-RC3643
Forge 1.12.2-14.23.5.2835
Crash and Logs:
Looks like you have a corrupted chunk. I am not sure if it is recoverable, but first try teleporting your player away from the current login and then restarting the server. If the issue persists, consider trying out a new world to test for mod incompatibility, or even disabling structure spawning.
If you want to try some hacky solutions, check out this server guide under “Fixing Lost Stability”. Maybe the first two solutions could apply.