This is a mystery to me and I hope you can help me out...
I have made an app that has got a QR-scanner and when accessing it on a fresh install on my iphone an alert is
Xcode 8.2.1, iOS 10.2.1
Just ran into the same issue. Please make sure you have a message entered for NSCameraUsageDescription and NSPhotoLibraryUsageDescription.
NSCameraUsageDescription
NSPhotoLibraryUsageDescription
To easily find these keys select "Show Raw Keys & Values" from the Editor menu.
Hope this helps.
Cheers.