Estoy tratando de presentar un UITableView que ya hice para que los usuarios ingresen datos y los guarden en el análisis. Estoy bastante seguro de que no presento la vista de navegación.

Cuando inicio sesión, me sale el error:

Checklists[4516:c07] Warning: Attempt to present <ChecklistsViewController: 0x10525e90> 
on <UINavigationController: 0x9648270> while a presentation is in progress!

Gracias por tu ayuda.

#import "LoginViewController.h"
#import "ChecklistsViewController.h"
#import "SetupViewController.h"
#import <Parse/Parse.h>

@interface LoginViewController ()

@end

@implementation LoginViewController

- (id)initWithNibName:(NSString *)nibNameOrNil bundle:(NSBundle *)nibBundleOrNil
{
    self = [super initWithNibName:nibNameOrNil bundle:nibBundleOrNil];
    if (self) {
        // Custom initialization
    }
    return self;
}

- (void)viewDidAppear:(BOOL)animated
{
    [super viewDidAppear:animated];

    PFLogInViewController *login = [[PFLogInViewController alloc] init];
    login.fields = PFLogInFieldsFacebook;
    // Need to set the delegate to be this controller.
    login.delegate = self;
    login.signUpController.delegate = self; //signUpController is a property on the login view controller
    [self presentModalViewController:login animated:NO];

}

    - (void)logInViewController:(PFLogInViewController *)logInController didLogInUser:(PFUser *)user
{
    [self dismissModalViewControllerAnimated:YES];
    NSLog(@"Successfully logged in.");
    ChecklistsViewController *controller = [[ChecklistsViewController alloc] initWithStyle:UITableViewStylePlain];
    controller.modalTransitionStyle = UITableViewStylePlain;
    [self presentModalViewController:controller animated:YES];

}