Crashes occur when placing conveyor belts from the Create mod or using portals from Ars Nouveau. There are no stable reproduction steps for this issue, but the crash reports consistently indicate that Entity Culling may be the cause of the problem.

https://mclo.gs/lxTHbbu
https://mclo.gs/f8XhPkn

Duplicate #225 , the crash says its "likely" EntityCulling from Sodium, I did add code that should prevent this(1.8.1+). Without a way to reproduce it, I can't verify that this is EntityCulling still, or just happens to be the boogeyman. Doesn't help to have more jank like Sinytra Connector in there too.

Also interesting that the other issue is NeoForge too, possible that it's releated.