Villager door crash issue

My 5 year old boy made this contraption in Minecraft and it caused a crash bug. It looks like there may be a contention issue with too many villagers accessing too few of doors. When a door is removed, minecraft crashes.

 

In creative mode, when you destroy one of these doors, minecraft crashed.  After I killed all of the villagers with a /kill command  I was able to remove the doors.