I have this issue with other things, but mostly twixtor. Whenver I try to slow something down I get an error that goes along the lines of "FCP cannot play this file... Try turning off unlimited FPS etc..." and then it flashes a box with lines through it on the screen. I can't find any sort of Unlimited FPS option, and when I export as a quicktime file, I just get a green screen until I get to the part where I don't use twixtor.
has anyone had this issue, and knows how to get around it?