Triangle on my pictures I have taken pictures on my iPhone 8 Plus but when I try to look at them on my MacBook running Sierra 10.12, they all have a triangle on them with an exclamation point. 

I am not able to edit the photos. What can I do to fix this?
I’m guessing your MacBook isn’t on High Sierra and you’re viewing the new photo formats. 

Have you looked at the settings app, camera, formats and checked JPEG instead of high efficiency? If you want to maintain high efficiency formats, upgrading now or eventually would be the plan.