Did you previously have MM 2020 and then accept the option to update to MM 2021? If so, you may have been caught out by the fact that the 2021 release is the first to be 64 bit and, as such, is a new program requiring to be purchased. Merely updating the 2020 version, even if you previously had the Plus or Premium variant, will give you only the Basic, Free version of MM 2021. To gain the full facilities of MM (and, if appropriate, to restore the functionality you had in any earlier version) you need to buy the Upgrade.
OTOH, have you tried simply dragging an .mp3 onto a track on the workscreen? Does it import successfully?
Thanks for the help. Dragging an mp3 onto a track doesn't work. Bit sneaky of Magix to use the update in that way without letting you know the consequences.😒
I have more than a little sympathy for your views!
However, as the post that @PATIENT-X linked shows, you can opt to simply add the features you really want; in the short term this may be cheaper than paying for the upgrade but if you want several of these features it is cheaper, in the end, to buy the full upgrade.