App is crashing on iOS6 with presentViewController, iOS5 works well

Question

This code is crashing when i run my app on iOS6 Simulator with Xcode 4.5 GM Seed:
if ([[[UIDevice currentDevice] systemVersion] isEqualToString:@"6.0"]) {
    XLog(@"hier checken");
    self.tabBarController = [[UITabBarController alloc] init];
    self.window.rootViewController = self.tabBarController;
    [self.window makeKeyAndVisible];
self.loginController = [[[LoginController alloc] initWithNibName:@"LoginController_iPhone" bundle:nil] autorelease];
self.loginController.modalTransitionStyle = UIModalTransitionStyleCrossDissolve;
//this line occurs a crash on iOS 6 (simulator, device not tested)
[self.tabBarController presentViewController:self.loginController
                                        animated:YES
                                      completion:nil]; 
The crash is a SIGABRT. no more information about the crash.
what is occuring this crash on iOS6?

Answer 1

Use the beta forums.