Minecraft crashes when I use a piston contraption while a block ID #36 is being ticked.
(The crash is exclusively on 16w40a).

What I expected to happen was...:
that it would function just like in 16w39c. In other words, no crash.

What actually happened was...:
a crash. Whenever the contraption is activated and the chunks are loaded the game crashes.

Steps to Reproduce:
I do not know the exact reasons for the crash but I encountered it in the wither ripper and I've checked that it happens in the original world so the best way to reproduce the bug would be to use that world.
1. Download the Wither Ripper world: http://www.mediafire.com/file/s9xe277l6iy6g0i/Witherripper+Ghast.zip
2. Activate the farm by pulling the middle lever at 135 31 -126
3. The crash should be imminent.