crash-2019-12-05_21.35.49-server.txt

On a server with 1.12.2 and 139 mods
The conflict is between this mod (OMPD) and Mekanism
It appears to happen on chunk load, though because it is a check for creature spawn I am not 100% sure.
It doesn't matter what Dimension the players base is in, because they have moved it multiple times, and this error keeps appearing randomly.
I have submitted this bug to the Mekanism github as well, which I will link here.

Seems to be fixed in Mekanism, closing this.

It is not fixed in Mekanism, they just closed the issue saying it isn't their problem.
Despite having fixed it in the past, now it seems they do not want to, which is why I also raised the issue here, hoping one of the sides of the error would know how to resolve it.

The issue is on neither of the two sides you mentioned, read the response and the commit in the issue on mekanism. It mentions its a Sponge bug and linked this: mekanism/Mekanism@29a3477