This is a sample Xcode project that crashes when the button "Present View Controller" is tapped. The question is: Why?
The issues seems to be that UIKit cannot create the connections for the outlet set in DimmedPresentationView.xib:
Terminating app due to uncaught exception 'NSUnknownKeyException',
reason: '[<_SwiftValue 0x610000052780> setValue:forUndefinedKey:]:
this class is not key value coding-compliant for the key closeButton.'
When you remove the outlet for the closeButton to the File's Owner in DimmedPresentationView.xib the app runs as expected without a crash. So why can the outlet connection not be established?