Since upgrading to Windows 10, ACID Music Studio 7 can no longer open mp4 files. It used to be able to, no problem, but now gives this message:

The file H:\Home.mp4 cannot be opened until it's plug-in has been purchased.

You can click the Purchase button to purchase the plug-in and continue using the file in ACID.

The Purchase button opens the defunct Sony website, and I haven't found any relevant plugins on the MAGIX website so now I'm stuck.

Does anyone know how I can fix this so I can open mp4 files again?

UPDATE: It seems that support for all .MP4 files has been removed from ACID Music Studio 7.