Ticking block entity crash with Industrial Foregoing mob crusher and mob slaughte factory

here is the crash report
https://mclo.gs/PvUXCk0

i set up a simple curse heart farm using the mob gringer and slaughter factory, i've yet to use DeepMobEvolution's stuf on this save
it randomly crashes to menu and once it does if i try to lad the save it crashes again
if i restart the minecraft instance it's fixed up until it happens again. AFAIK there's no particular trigger 