. . . . Magix-program does produce audio when I import mts-files. What to do? . . . .
Read this topic and come back with more information ie your laptop specification, Windows version and Movie Edit Pro version and MediaInfo data on one of the clips you are trying to import - details are in the linked to post.
Did you also install all the free extras that come with the program?
If the video clips are surround sound, did you activate the Dolby Surround Sound codec - you should have been prompted to do this on first import?
As I said above, you should be prompted to do so on first import if your source video has Dolby Surround Sound.
We still need all the information requested - help us to help you by providing all the requested information in detail as listed in the topic I linked to.
Finding the correct solution depends on accurate information and may be delayed due to repeated requests for more information.
Also did you read this topic? Although it relates to Video Pro X it is also relevant to Movie Edit Pro.