I assume you mean Magix Music Maker Premium 2015, if so please use the full name number or abbreviate to 'MMM 2015' to avoid confusion with older versions of the program.
In the Programs settings, Playback tab you will find that MMM 2015 is using the ASIO settings, change them to one of the other options - Wave driver or Direct X. In the image below you can see I use the Wave Driver
Same issue here as ericInz with Vegas Movie Studio 14 MMM 126.96.36.199 on Win10. I could not work it out, and if I wanted to watch any tutorials or youtube, I had to exit MMM. It was doing my head in. Now its fine with a change to wave driver. Can't you guys make wave the default driver at install, so this issue doesn't happen, as it will turn many people off this what seems to be, a fine product. I was just about to flick it until I came here and read this.
The problem I have is that when I select Wave driver, then the latency using my mdid controller becomes very slow. How can I play the midi sounds in MMM as well as listen to playback from another mediaplayer?