Freeze when entering Pixelmon's Ultra Space dimension

[vainlaind4in]

Minecraft freezes and crashes immediately when entering the ultra-space wormhole which is present in Pixelmon. I do enter the dimension, but nothing loads and the game stops. The log also shows that Worley's Caves is also causing errors out alongside Yung's Better Caves.

I've also submitted an issue to Worley's Caves about this as well, as I'm not sure which mod is conflicting here.

Versions:

Minecraft: 1.12.2
Worley Caves: 1.5.2
Better Caves: 2.0.4

Log