--- Objective-C --- I can't find a way to fix this: Thread 1: signal SIGABRT

I'm trying to build the simple iPhone app with Objective-C: fun fact. at one point the view stopped showing up when I clicked run. I've fixed that, but when I click the button "show another fact!" it returns to the code with the following:

In main.m the following is highlighted:

int main(int argc, char * argv[]) { @autoreleasepool { return UIApplicationMain(argc, argv, nil, NSStringFromClass([AppDelegate class])); }

}

In ViewController.m the section connected to the button is connected:

• (IBAction)showFunFact {

  NSArray *facts = [[NSArray alloc] initWithObjects: @"Ostriches can run faster than horses.", @"Dolphins sleep with one eye open.", nil];

  self.funFactLabel.text = [facts objectAtIndex:1];

  }

In ViewController.h the section for this screen is:

@property (weak, nonatomic) IBOutlet UILabel *funFactLabel;

The main.h and main.m areas are already provided in a template.