App closing

I really like this app. However, Im only on day 4 or 5 and Im trying to do the next workout and it keeps closing :/ I deleted, added and restarted my iPad and its still not working. Im wondering if it has anything to do with the fact that I missed yesterdays workout, turns out it was a rest day. Im trying to do the next one and thats when its closes. Maybe it doesnt allow you to do more than one day at a time?

RJSN2012 about 30 Day Fitness Challenges, v2.0.0