Playback

I recently downloaded Musescore 2.0.3, after having a previous version, being 1.3.

As soon as I open my piece, I naturally want to start listening to it and change some things, except musescore won't allow me to play anything back at all. It doesn't give me an option. At first, I tried deleting the previous version, which helped for one day, but then hop onto musescore expecting it to work fine the next day, only to find that it doesn't and nothing happens at all. The play button and anything to do with playback is grey, even after note selection.

Any fixes? Super annoying.