Cannot create a noise reduction profile

Cannot create a noise reduction profile.
I have loaded an Mp3 file and selected a region but when I select effects/noise reduction I get the error

You must first select some audio to perform this action.
Selecting other kinds of track won’t work

Any help appreciated
Toni

I kinda sorta remember something like that happening to me a while back. I think it turned out that I was selecting from a label track instead of an audio track.