Blank videos showing in iPhoto app

I have an iPhone 5S iOS version 8.3, and I noticed when trying to sync my videos to my MacBook Air that it was giving me an error message. It couldn't upload due to a problem with the files. When I looked closer, I saw there were a bunch of videos between a certain date range that were showing as blank. See picture. I've reset the phone, and this problem existed prior to my version upgrade. When I try to play the videos, it looks like they're playing because the play button changes to a pause button. There is no sound or duration lapsing and the screen goes black. I've found one similar discussion thread in a different forum but I don't see a resolution there. Can anyone help? Not only do I want to try to save these videos if I can, I want to make sure there's not an issue with my phone that will damage more files.