File copy fails on FCPX created .mov

Have a project I'm trying to backup. One of the "Final Cut original media" folder files, a .mov, fails to copy completely. It gets about 50% done, then the transfer freezes. Tested on different target drives, same problem. The other 70 files no problem. That same MOV inside FCPX has no issues with playback, etc.

The problem MOV file was one of 20 created from a C300 mki, which generates MXFs on the camera card. FCPX creates mov on import. An odd thing is that in "original media" are all the camera card MXFs from 1 of the 2 camera cards from that C300 in addition to the FCPX created MOVs. And they are in the FCPX event. Not needed as the MOVs combine them into 1 file. Anyway, I digress, just another curiosity on this import.

So any ideas why 1 MOV won't complete a Finder copy operation, yet appears to be 100% OK within FCPX?

In the Finder, right-click that file, Compress it, see if the resulting zip file will copy. Then double-click to uncompress. But that is odd. Did you optimize it or create a proxy of it inside FCPX?

Well, that worked. But then I also tried original copy operation, and it worked as well. However, I had down a system reboot just a few minutes ago, so it appears that was the real fix.

Probably some file system indexing thing that got wonky.

So my mistake was not following Rule #1: When things get weird, reboot.

Thanks!