Well goddamnit, I just downloaded 4.3 and it still will not take my FCP movie. I tried delteing the extension and changing it, to no avail. It’s a 13.5 minute uncompressed movie 8 bit SD NTSC.
I used QT movie from FCP, self contained, do not recompress, same codec as sequence which is DV NTSC. But as I said, I have the same problem from 8 bit projects exported the same way.