I broke tall grass and it killed the client. just a note it could be something to do with other mods because i have more than 500 of them running.
if you need anything just say and i will try to add it for you.
crash-2018-03-25_20.48.56-client.txt

I can't reproduce in my tests. Also Koentus Block still unobtainable in survival except Creative Mode.

Due to remove metadata from block, this should be fixed.