DV PAL clips appear Black in Browser and Viewer?

I have some old DV PAL clips that were imported some years ago . . . can't remember whether I used legacy FCP or FCP X but appear perfectly normal and play correctly in QT.

When I import them into FCP X, the image in the Browser and Timeline is BLACK!

The project properties are CUSTOM: 768x576 at 25p

When I try to render the footage, the rendering goes up to 100% and then repeats ad infinitum!

I have never had these problems before when dealing with DV.

Is it a Catalina problem?

Any ideas?

PS. I have also used the normal DV PAL preset with the same results.