Done and Cancel button hides

[IrfanMarwat]

Some time done and cancel button is not visible. I am able to press on those areas, but buttons are not visible on iOS 11.

[bkischel]

I faced the same issue but I think they are not hidden - their tintColor is just white.
You can solve this by moving this definition in QBImagePickerController.m

@property (nonatomic, strong) UINavigationController *albumsNavigationController;

to the QBImagePickerController.h file so that it is accessible by an object of QBImagePickerController.
Now, you can change the tint color in your code:

self.imagePickerController = [QBImagePickerController new];
//...
self.imagePickerController.albumsNavigationController.navigationBar.tintColor = UIColor.blackColor;