We need more information - see this topic and come back with your computer specification and which program you are using - details required are in the topic linked to.
Also include a MediaInfo analysis of one of the video clips you are trying to import.
However, you selected "Other Products" as your Magix software so we have no idea about which software you are using (as @John EB pointed out). Without that information, we are extremely unlikely to be able to help you!