Playback and Tempo Issues

If I am trying to start listening to my show halfway through it just freezes and doesn't play. it works from the beginning but it will not work if I start it at a different measure. Idk what to do about this and it is making it really hard to write. Any suggestions on how to fix this? Also, the Tempo will not change from 120. Don't know what to do about it. Very frustrated, Please Help!