I recently discovered how to use the /scoreboard command to have Shulkers attack other hostile mobs. I was testing them out as a defense mechanism for a Nether base. Having previously seen them attack Zombies, Zombie Pigmen, Creepers, Endermen, Skeletons, Wither Skeletons, and Guardians, (and having seen Skeletons return fire and hit the Shulker without issue), I spawned a blaze nearby the Shulkers.

I assumed the Shulkers would attack the Blaze, and the Blaze would retaliate.

The Shulkers did indeed attack the Blaze, and the Blaze shot back, but when the fireball hit the Shulker, Minecraft crashed. I tried to re-load the world, and it crashed again. I tried in another world, and the same thing happened.

Steps to Reproduce:
1. Spawn a Shulker
2. Use /scoreboard to create a team.
3. Use /scoreboard teams join @e[type=Shulker] to put the Shulker on the team, causing it to attack hostile mobs.
4. Spawn a Blaze.
5. The Shulker will attack the Blaze, who will then shoot back. As soon as a fireball hits the Shulker, the game will crash.

I can post the crash report if necessary.