Hard work to deal with state restoration in iOS

Question

How to deal with "Warning: Unable to create restoration in progress marker file."

1. I have assigned the Restoration Ids to my view controllers in main story board.

2. I have also assigned Restoration Id to the view controllers created by code.

For example:

 @interface BEMenuController ()<UIViewControllerRestoration>
    .....

    + (UIViewController *) viewControllerWithRestorationIdentifierPath:     (NSArray *)identifierComponents coder:(NSCoder *)coder
{    
    UIViewController *retViewController = [[BEMenuController alloc] init];
    return retViewController;
    }

    - (void)viewDidLoad
    {
    [super viewDidLoad];
    
    self.restorationIdentifier = @"BEMenuController";
    self.restorationClass      = [self class];
    
..........
    }

3. I did as in following link asked

state restoration in iOS

Now the problem is when I run the application I am getting the following warning also:

• Unable to create restoration in progress marker file.

Not sure what else need to be done.