Chests in Survival are disappearing after re-entering my world

MCPE 0.7.6 - When I entered my world today, I went into my house to take some wood out of my chest. But all my chests were not there anymore. By hitting the place where one of my double-chests was before, suddenly a single chest appeared there but it was empty.
The same thing accured on all other chest places. And they were all empty.
I didn't find a bug like this yet in the internet.

What I expected to happen was...:
I wanted to open on of my chests to take something out of it.

What actually happened was...:
All my chests were not there anymore. By hitting there old places, empty single chests appeared.

Steps to Reproduce:
1. Enter the world
2. Try to find the chest

I think that I am the only one with this bug at this time.

And sry for my bad english.