Mac VideoComponent blank screen

Our app uses VideoComponent to playback mp4 videos. It works just fine for 99% of our users. But every once in a while we get a user that reports the videos playing back with a blank screen. And by blank I don’t just mean black. It’s invisible, showing the background that’s behind it. It does however play the audio fine.

I’ve tried providing them with any codecs they might be missing in /Library/Quicktime (though I’m not sure if this would matter since the VideoComponent uses AVFoundation now) but that doesn’t seem to work.

Has anyone else experienced this? Does anyone have any theories? I’m drawing a blank (no pun intended).