Game crashes when you are hit by a zombie holding any item that doesn't have a set damage value, like a sword, steps to reproduce:
1. run this command:

/summon Zombie ~ ~1 ~ {HandItems:[{id:bone,Count:1},{}]}

(also happens with natural/spawn egg zombies command is just for ease of testing)

2. go into gamemode 0 and get hit by the zombie

Also affect the zombie pigman/husk/skeleton(wither)/husk