I don't know if this is exactly what happened, but here goes.

What I expected to happen was...:
My chest to be visible when I came back from mining.

What actually happened was...:
I came back and thought it broke itself, but in reality it was invisible. I couldn't fix it without breaking it.

Steps to Reproduce:
1. Play Minecraft in survival.
2. Open to LAN and turn cheats on. Also set /gamerule keepInventory true
3. Die (I died from lava holding a stone sword)
3. When respawned, your chest may be invisible. I don't know.

To be sure, I was in 14w32b and had iron and diamond designed to spawn a lot in one vain, along with more frequently. The chest had a visible hitbox but the texture was not visible. It was on polished diorite. If any other information is needed, please contact me.