On my iMac 21.5 Late 2012 I cannot go Full Screen in any application; It just makes an 'error' sound. I used the Control + Cmd + F and it still made the error sound. I am using OS X Mavericks 10.9. Please help.
Also, I restarted my Computer when this happend.
What happens when you hit the the double arrow that looks like:
in the upper right of the display??
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