Error SIGBART in XCode iOS

Error SIGBART in XCode iOS

I have a program with different components, but when I compile, I get
signal SIGBART every time. The main purpose of my code is to change a
boolean when the user moves, set text to a variable when a button is
tapped, and set a string to do/don't with the press of different buttons.
My code is below:
ViewController.m
#import "ViewController.h"
@interface ViewController ()
@end
@implementation ViewController
@synthesize mapView;
@synthesize dodont;
@synthesize reminders;
- (void)viewDidLoad
{
[super viewDidLoad];
mapView.showsUserLocation = YES;
on = @"don't";
dodont.text = on;
}
- (void)didReceiveMemoryWarning
{
[super didReceiveMemoryWarning];
// Dispose of any resources that can be recreated.
}
- (void)mapView:(MKMapView *)mapView
didUpdateUserLocation:
(MKUserLocation *)userLocation
{
move = TRUE;
}
- (IBAction)enable:(id)sender {
on = @"do";
}
- (IBAction)disable:(id)sender {
on = @"don't";
}
- (IBAction)save:(id)sender {
content = reminders.text;
}
@end
ViewController.h
#import <UIKit/UIKit.h>
#import <MapKit/MapKit.h>
NSString *on;
BOOL move= FALSE;
NSString *content;
@interface ViewController : UIViewController {
MKMapView *mapview;
}
@property (weak, nonatomic) IBOutlet MKMapView *mapView;
- (IBAction)enable:(id)sender;
- (IBAction)disable:(id)sender;
@property (weak, nonatomic) IBOutlet UILabel *dodont;
- (IBAction)save:(id)sender;
@property (strong, nonatomic) IBOutlet UITextView *reminders;
@end
AppDelegate.m
#import "AppDelegate.h"
@implementation AppDelegate
- (BOOL)application:(UIApplication *)application
didFinishLaunchingWithOptions:(NSDictionary *)launchOptions
{
// Override point for customization after application launch.
return YES;
}
- (void)applicationWillResignActive:(UIApplication *)application
{
// Sent when the application is about to move from active to inactive
state. This can occur for certain types of temporary interruptions
(such as an incoming phone call or SMS message) or when the user quits
the application and it begins the transition to the background state.
// Use this method to pause ongoing tasks, disable timers, and
throttle down OpenGL ES frame rates. Games should use this method to
pause the game.
}
- (void)applicationDidEnterBackground:(UIApplication *)application
{
// Use this method to release shared resources, save user data,
invalidate timers, and store enough application state information to
restore your application to its current state in case it is terminated
later.
// If your application supports background execution, this method is
called instead of applicationWillTerminate: when the user quits.
}
- (void)applicationWillEnterForeground:(UIApplication *)application
{
// Called as part of the transition from the background to the
inactive state; here you can undo many of the changes made on entering
the background.
}
- (void)applicationDidBecomeActive:(UIApplication *)application
{
// Restart any tasks that were paused (or not yet started) while the
application was inactive. If the application was previously in the
background, optionally refresh the user interface.
}
- (void)applicationWillTerminate:(UIApplication *)application
{
// Called when the application is about to terminate. Save data if
appropriate. See also applicationDidEnterBackground:.
}
@end
AppDelegate.h
#import <UIKit/UIKit.h>
@interface AppDelegate : UIResponder <UIApplicationDelegate>
@property (strong, nonatomic) UIWindow *window;
@end