I think I find the solution of the problem about Dread Thrall

[MarkIc5785]

#80
It seems that one of the plugin for jei or waila causes this, but I forgot which one. Seems like the one can show the armor info of entity. Not sure.
I was holding a server with e2ee last year, and I happened to see some posts with similar problem. We just removed that mod and everything was fine. After looting mauselums we just take it back and keep away from this area.

[Krutoy242]

As far as I know, this happen even if you don't look at the mob at all and just somewhere near it.
Isn't waila working only when you look at the mob?

[MarkIc5785]

Well, the problem occured only when we look at the mob. Mob wandering around, or getting close to (or even getting into, as long as we don't see the mobs) the Mausoleums don't cause the problem for us.
They might be different problems.

[Krutoy242]

Yes, probably different problems. When i encountered this error, its appens in about 50-100 blocks from mod, out of reach and even if you looking opposite direction.