Crashing when recording video

I recently purchased the Mixvibes pro version and made the in app purchase to enable full video use. So far every time I try to record to video tracks mixed together it crashes. It is fine whilst each individual track is playing and during the mix, it is always after when the recording is saving that the programme closes and the box appears saying that Mixvibes closed unexpectedly.
Can anyone please help me with this problem?
Many thanks
Can anyone please help me with this problem?
Many thanks
