Can't click on ship parts

[Murray]

I have KSP on my MAC, was running fine until i decided to try and right click on my command module, i then realised that i couldn't select any ship parts. 

For example, i cant select solar panels to extend them or light to turn them on, the only thing i can select is the crew hatch.

Please help! love the game and played it when it was in early access and loved it! Thanks!