A Revision of an Adobe AIR app (educational app for kids), Source code is available

Dear Freelancers, we need someone who revised our app. For this I´ll you give the source code and some other files. The software consists of two lessons: reading and calculating. Each of them are 24 and 27 weeks long with seven days a week. After a sequence of five words or numbers that the kids learn you have to go to the next day. And here´s the bug. While the reading lesson works fine and goes through all 24 weeks the calculating lesson worries us. The calculating lesson ends in the 10th week on day 6 with a white screen. Watch the video that I've attached. Unfortunately, it can not continue. I had the problem before with the same week 10 but day 3. The app has been looking for an audio file that was not there. The bug comming with the "[login to view URL]". In the lessons it searching "a483" audio and "m483" movie clip. It was a transposed number because the Week 10 Day 3 should continue with a408 / m408. The bug was solved. Now I think we have a similar problem in the same week. What I need is a freelancer who can revised the calculating lesson and the most important thing is that he is reliable. My last Freelancer was no longer accessible after a short time. This is annoying because I also need someone who is available for future projects and problems. Ok, at first my educational app needs to work well. If you're interested I´ll send you the code and the math order as an Excel file. Thanks in advance or all you offers and have a nice year 2015 Best wishes Christian