File format cannot be found

I have an mp4 file on my pc and I'm trying to drag and drop it into the editor in MAGIX Movie Edit Pro 16. I have Windows 7. Why is it so difficult to use MAGIX products on Windows 7? If you say you're Windows 7 compatible why all the issues? This is my second issue with MAGIX products and it's getting annoying.

I've spent the money to buy the mp4 activation thinking maybe that would help but nope. I read that deselecting acceleration for high res mpeg files would help. I didn't have checked to begin with so what can we do to alleviate this problem?

Thank you.