I'm having the same issue and it's only when trying to place a voice memo or video that someone has TEXTED. If someone texts me a voice memo or a video clip, and I try to view it using bitesms, I get this error, "This movie cannot be played".
Now, I can view them if I use apples text app perfectly, but not bitesms. The same thing happens on my other two friends iphones with the same version of bitesms 5.3. But if you use apples text app, they play fine. This is a bug somewhere I think. This is what you are saying, yes???
Thanks,
Jason