Okay for even further intrigue, FCPX was saying it couldn’t link clips because the original file “didn’t have audio, but the new one does”, so I had the idea to run one clip through davinci, export the same codec/container etc., but remove the audio channel, and then try and relink that file (I don’t need the audio off the video, so this could work as a solution).
Then FCPX say:
“The original file didn’t have video, but the new file does.
Relinked files must have the same media type and similar audio channels as the original files, and must be long enough to cover all the clips that reference the files.”
Which is obviously a foolish statement, silly FCPX.
So uh… any idea out there what’s going on?