Crashes When Attempting to Present Side View Multiple Times

[spiderguy84]

I am having an issue with PKRevealController code from GitHub crashing my app. I set it up right:

 WebViewController *rightView2 = [[WebViewController alloc] initWithNibName:@"WebViewController" bundle:[NSBundle mainBundle]];
        PKRevealController *revealController = [PKRevealController revealControllerWithFrontViewController:tabBarController leftViewController:rightView2];
        revealController.delegate = self;

       window.rootViewController = revealController;

        [window makeKeyAndVisible];

And in the viewController I want to call it from I add this:

 - (void)startPresentationMode
    {
        if (![self.revealController isPresentationModeActive])
        {
            [self.revealController enterPresentationModeAnimated:YES completion:nil];
        }
        else
        {
            [self.revealController resignPresentationModeEntirely:NO animated:YES completion:nil];
        }
    }

When I click the button to start that code, it slides over and shows the view just how I want it. Clicking outside of the side view even slides it back. But, if I click the button again, I simply get a (lldb) crash in console. If I add an exception breakpoint, it shows me a line in PKRevealController:

NSAssert([self hasLeftViewController] || [self hasRightViewController], @"%@ ERROR - %s : Cannot enter presentation mode without either left or right view controller.", [self class], __PRETTY_FUNCTION__);

What is exactly the problem going on?