Imported clips are all black

When importing clips from 5D mk3, alle clips, besides 2-3 images turn out black. The preview clip is black, but the 2-3 first seconds of the clip shows, but after that the all go black.

To fix this I had to import my clips via EOS utility to my hard drive, and then import the clips from my drive to FCPX. Any idea why the turn black when importing directly from the camera?

Sierra 10.12.2
FCPX 10.3.1

I had a similar problem yesterday with C100 II footage. Eventually the video showed up (the audio was fine). It was as if the SD card was taking forever to be imported which was odd as it was a 2 minute clip. Came back about ½ hour later and the video was there. It made no sense at all. When the problem first appeared I found the card in Finder and played the clip with QT and everything was fine so it seemed to be inside FCPX that something malfunctioned.

Tried to repeat the problem so I could report it but it wouldn't repeat. ?????

Still doesn't work here. Thumbnail is black, and only the three first seconds show when skimming.

Same problem here....

imported fine on a PC.. just not my MAC

Anyone know what might cause this?

Anybody? Nothing helps here. The only thing I haven't done is to reinstall OSX, and that's not going to happen.

What computer do you have?
Also is there a Canon import plugin ?

It`s a new iMac, 27" 4.0 ghz.
Didn`t have the problem before. Perhaps after installen Sierra the problem occured.

Canon import plugin? Like Eos utility?

Am I the only one with this problem?

Am I the only one with this problem?

No, but you're the only ones looking for a solution using a particular camera right now. I think you'd get better advice from a user forum dedicated to your camera or to the codec the camera uses.

Over on apple.com/fcpx we've seen similar posts form GoPro users and C100 users: black video, sometimes with audio, sometimes not. Sierra might have been part of the problem but none of the sufferers seems to have the patience to do any tests that would answer that question.

I have tried everything. I have contacted Apple, but they don't know what's wrong either. Updated cameras firmware, updated a driver. But it doesn't work. The clip is actually corrupted after importing from camera to fcpx. But the workaround works fine. The specs between the two identical clips are identical, so why it gets corrupted during import is confusing.
I don't know what more to try. Try another 5D mk3 is one way, but I don't know any with it. So I need to reach out.