I have a simple map application using openStreetMap that works well on all iPhone simulators ( xcode 6.1, IOS 7.1 & 8.1 ). However, when I compile on a real device (iPhone 4 iOS 7.1), I encounter some issues (see screenshot), the application doesn't recognize some classes, such as MKTileOverlay, MKOverlayRender, etc.
The weirdest thing is that it worked a few weeks ago, then, after I worked on another project, when I come back to this one, the problem appeared.
Maybe the problem is coming from Xcode or the device's configuration? I searched for several days, without success, so could someone tell me where I went wrong?