Glitch where a falling sand entity of a chest that lands turns into sand, but is with the wierd purple checkered texture and crashes when punched, or pushed by a piston.

This is my first bug report so sorry if it has not enough info...

I used SethBling's spawn structure filter in MCEdit

What I expected to happen was the block would update and disapear.

What actually happened was it crashed the game but the server is still upand running fine :

Steps to Reproduce:
1. Make a spawner minecart that spawns a chest falling sand entity in a exact spot in the world. I had it on wood.
2. Break spawner minecart and go to where chest is.

If it doesn't work I have a screenshot attached

After some experiments with pistons I found the ghost the blocks act like sand... even have the sound of sand.