Exactly which Magix product do you have? You have posted to the Movie Studio area of the forums but your mention of vegas leads me to wonder whether you have Magix Movie Studio or Vegas Movie Studio or even Vegas Pro.
If your software is either of the two Vegas products you need to read this pinned post and follow the advice given there. Especially since your error message seems to refer to the Main Concept codec which is not available in recent versions of Magix software I believe, due to deprecation.