If you want to enable anyone to offer any kind of help that is not just random guesses, you need to provide way more information. Always make sure to specify the program and version you're using, with any enquiry. With this problem in particular, you should provide details regarding the video source material you're using. What format is it (file format, video codec)? Where does it come from? What resolution does it have? That would make it much easier to help. Magix technical support might also be a good place to ask this kind of question.