I updated to 0.11.0 and I booted up one of my world's that I had from 0.10.5 and I couldn't break any signs! And later I updated to 0.11.1 and I still couldn't break any signs! What the heck. The game sees it as a ghost entity. I cannot interact with it and I can even put blocks in the Same place as the entity.
Duplicate of MCPE-8705