I have Music Studio 12 where I made dozens of VIP files. I get Music Maker 16 and it won't accept them at all.
When importing MIDI files, Music Studio 12 let me put each MIDI track into one VIP line so that I can give each instrument its own sound. You can't do that in Music Maker 16. It all goes to one line and I can't find a way to separate the MIDI into multiple tracks.
Keep in mind that you're talking about two completely different product lines here. Music Maker 16 is not the update to Music Studio 12. Music Maker is a different product line. Music Maker is closer to the Magix video editing products, as far as internal engine and interface are concerned. Music Studio is derived from Samplitude (Magix' pro-audio product line). So, the two file formats don't really mix.
This here would be the real successor to your Music Studio program:
Not completely positive whether it would open all of your old VIP files without any problems as there have been a few product generations in between, but I guess you could try with the demo version from the website and see how that works for you.