Cannot take footage off camera (2C)

Just installed 2C cameras and Homebase 2. When I transfer footage to phone it plays, but if I airdrop to MacBook it appears as an mp4 file. But nothing will open or play it. Errors say being used by another application and cannot convert etc. Anyone else resolve this problem? I can get it into I Photo, but cannot drag onto desktop for example and VLC and QuickTime players cannot open it either.