Put the summary of the bug you're having here

What I expected to happen was...:
The door would open and I would go through it.

What actually happened was...:
Game crashed

Steps to Reproduce:
1. Made 4 sticky pistons with gold blocks to act as door
2. had 2 stone pressure plates on each side to activate it
3. whenever I go through it crashes the game

(This is on a private whitelisted server where we always play on the most recent snapshot and I have lots of other redstone around which could be causing it)

I attached the crash report as a txt file