Musescore not responding....

After 4 years of loyal service Musescore has decided to pack up on me. Was working fine up until yesterday, a brilliant program. However, after inadvertently allowing my computer to enter 'sleep mode' with Musescore still running, it is now unresponsive and none of the fixes seem to work. Starting/restarting; toggling MIDI button etc. have no effect. The program will allow me to enter a few notes (no sound) but will freeze. This freezing can also be achieved by pressing 'play'. I've four years of degree material on Musescore and was loving it. Please help!