More than 5 tabs and pushViewController

I'm having difficulty understanding why this isn't working. I have 7 tabs on the UITabBar so conviniently Apple replaces them with 5, one of which is a 'More' tab. My tabs contain views with a table view in each of them and when a cell is selected it then displays another view via pushViewController from my navController file. This works perfectly until the tab is forced into Apple's 'More' tab. When I select the tab inside the 'More' tab the same table view displays as normal, however, when a cell is selected nothing happens and when the cell is selected again or another one, it crashes with a SIGABRT error. Can someone enlighten me as to why my existing code no longer works when the view is shoved into Apple's 'More' tab?

Thanks

 

Fixed by replacing my subclass of UINavigationController to self.navigationController.