Hi,
I tried to open a photo, shot with my iPhone, but there is only the screen which you can see in the screenshot below. I stoped after about 5 minutes of waiting and tried again, but it's the same problem again. I tested an other photo, shot on the same day, also shot with the iPhone and it's working fine.
I have iOS 10, and Affinity Photo, both latest release, iPad Pro 12.9 1st generation.