Hello guys, I'm an owner of traktor pro 2 and traktor kontrol s2

I recently move to windows 7 x64 from mac cause of mac malfunction and I have a question

Traktor won't play any of my 50000 m4a tracks. Why is that ? It displays an error named

"Cannot analyze BPM due to missing transients"

is there any fix for that or istalling a codec or smithin before converting all that stuff ??

thanks in advance.