I've been getting this crash every couple hours while playing. https://pastebin.com/JNBKQHst Not 100% sure whether it's chisel or codechicken that is causing the error, I just know that they are both involved in the crash. I'm thinking it may be caused by the fact that i'm using an efficiency 15 pickaxe to instant break blocks.

If you cannot reproduce it without CodeChickenLib then it is assumed to be their bug, as they are the ones calling this method with an invalid stack.