Videos won't play in photos and Quicktime won't convert the video
I can't get some of the older (2015) videos to play in photos. When it asks if I want to play it using Quicktime, I click Okay and the Quicktime window pops up showing it is "converting" but then it stops and says "QuickTime Player can't open..." The video was taken using an iPhone 5s and is a ".mov" file.
What else can I do to get the videos to work? I have A LOT of videos of my kids growing up and a majority of them won't play now....
MacBook