I shot all afternoon with a Mavic 2 today. All mov files can be viewed fine through the App but when I import them into a Mac running Sierra 10.12.6, no application can do anything with them. The folder is 30gb and there are 42 files there so the content seems to be there. Is this a codec issue? What am I missing here?

Upgrade to macOS High Sierra.

I wouldnt be surprised if you filmed in h265 format?
Or what format/mode did you shoot in?

Hi there, sorry for the inconvenience caused. I suggest you update the ios of your Mac into the latest version for reliability purposes. Should you have further question, please let us know. Thank you.