Using Vegas Pro 15, some .mov files (from Canon 5D Mark IV) included in projects that I edited last week are now totally black in vegas. There not muted or so. Their sound can still be heard. I've tried deleting their .sfk temporary files to let vegas rebuild them. This does not affect other similar files from the same cameras+same filming session, oly some of them. These files play normally in VLC.

Edit with some more info: they are black in preview and rendered files, they are not black in timeline.

Any idea? Thank you.