I tried to find the solution, but I couldn't find anyone with the same problem.
I'm using Xcode 8.2.1, writing in Objective-C.
I'm actually having a problem with adding a UIImageView to IBOutletCollection. I'm trying to do it using the Interface Builder.
dragging to connect ImageView with the Collection
I've already deleted any existing outlets of that ImageView.
I'm also adding screenshot of the header file of the MasterViewController - I guess everything is OK here.
Thanks for help.