DismissViewControllerAnimated is not working

Working in local push notification if the notification recive its move to NotificationViewcontroller there is no notification it move the main view controller here I'm using code - (void)applicationWillEnterForeground:(UIApplication *)application {

if ([status isEqualToString:@"YES"])
{
     NotificationViewcontroller *notify_view =[[NotificationViewcontroller alloc]init];
    [self.window.rootViewController presentViewController:notify_view animated:YES completion:nil];

wen in use this code means it should not move to NotificationViewcontroller i got this error whose view is not in the window hierarchy!

   // self.window.rootViewController=notify_view;

i use this code it move to NotificationViewcontroller. after see the notification put one back button to go view controller

    NSLog(@"Go to some other view");


}
else
{
    [self.window.rootViewController dismissViewControllerAnimated:YES  completion:nil];
}

After see the notification put one back button to go view controller that back button is not working.

-(IBAction)back_btn:(id)sender { [self.window.rootViewController dismissViewControllerAnimated:YES completion:nil];

} help me!!!! I'm new for development...