Please describe the problem:
I once selected full screen mode, and can't get out of it. The navigation symbols cannot be seen at the top right of the screen. If I press F11, or click on the "leave full screen" icon a smaller window appears momentarily, but then the full screen window immediately returns. To exit I have to press <Alt><F4> or some such. 
(Sorry, but I can't even access the Help menu, so don't know what version I'm using, but I installed it only a week or two ago, so it must be pretty recent.)

Steps to reproduce:
1. Don't know! I only selected full screen once.
2. 
3. 


Actual results:
Same answer, I'm afraid.

Expected results:
I would hope that the "leave full screen" button, or F11, would return me to the previous window.

Does this happen every time?
See above.

Other information: