When molten steel is poured into the casting basin with a mold, it disappears instead of solidifying into steel.
This bug is really critical in the means of getting into steel age.
Without steel it is impossible to create distillation and some electrical buildings.
And without them this mod is pretty much useless.

There is a way to fix this but only works in singleplayer.
Players will be stuck with it on servers unless the admin applies the fix to the server files as well.
Deleting the "amogus.json" file from "tfmg-0.9.3-1.20.1.jar\data\tfmg\recipes\casting\amogus.json" somehow fixes it.
Even after that it may dissappear from time to time but lesser.
Casting basing won't work with some item transportation methods as well , like hoppers delete the steels.

Literally experienced this live just now unknowingly so I gotta use IE blast furnaces instead