I have Vegas Magix Movie Studio 16, but this problem started with a previous version - 14. I've been using this software since version 7. All of a sudden (perhaps after a Windows update? - not sure) I get an error message that says AAC/MC has failed. Now I can't import many .mp4 video files and I can't render an .mp4 file. I've been emailing Magix Customer Support back and forth for weeks, and the only advice I get is to sign in as Administrator, which I've done every way possible (including the hidden Windows administrator) without any success. Can you help me? I'm using windows 10 on MSI laptop. Working fine till about 2 months ago.