When I try to destroy any objects, with hands or weapons, the game doesn’t register anything. I can’t attack, break blocks, or destroy things like torches and grass. I can place items and blocks. I have tried playing in creative, survival and multiplayer and I have the same bug.  When I play on my friend’s server, I am the only person that is having this bug, so I know it is on my side.  I have tried uninstalling the application, with no luck.  I've also tried going into controls and testing different keys. 

• • I was playing for a little bit before this issue started occurring, so it has nothing to do with my computer's capability.  I'm using a Macbook Air.

I vaguely remember trying to find how to get the coordinates to pop up during game play when this issue started, maybe it has something to do with pressing certain keys?