Score Playback Problems

I have had trouble recently with not being able to playback my scores. I still have all the other functions but the buttons between the metronome and the midi input ones are all grey and cannot be pushed. This has happened in the past and then I would just restart the app to fix it, however now this is not working. I have even tried restoring the app's factory setting and none of these things have helped so far.

Suggestions?