I've recently upgraded to MS 18 Suite - when I add MTS files from my Sony NX3 Camera - it won't display the file, it did download a codec MPEG 4, with no luck displaying the video.
My older version MS 15 works fine, not sure where the problem lies.
IM using WIN 10, have a DELL I5 Desktop with a dedicated video card.
Unfortunately Movie Studio 18 is not a VEGAS product, it is a version of Magix Movie Edit Pro, which is quite different. Support for it is not available on this site. However, support for Movie Studio 18 is available from the Magix user forum at https://www.magix.info/us/video-forum/.