F3 Concordance search suddenly doesn't work in review mode. Tried everything suggested in earlier posts but nothing works...

 Hello!

Suddenly F3 doesn't work anymore in Review Mode in Stuido 2015. Nothing happens, no window appears and the shortcuts in the ribbon are greyed out. I tried restarting Studio and restarting the computer. I renamed the file in appdata, I created a new shortcut, nothing works.

Anything else I can try? Because this means I cannot use Review Mode anymore...

Hope someone can help!

Sara