Hello,

the Fan is a bit weird (I don't know, how to create gif's :D )->

During it rotates it change from white to black (short : Its flickering)

MC 1.12.2
OpenBlocks ->1.7.4
OpenLib ->0.11.4
Forge ->2584

Sorry, I don't investigate rendering glitches when Optifine is present. Especially when this issue is not reproducible without it.

Ohhh, sry. In 1.7 it worked with Opti"fine" ( :D ) thats why I thought it is a problem.