c# - Error when adding UITabBarController -

i'm using monotouch c# write iphone app number of different screens. keep things simple describe few screens lead controller having issues with.

the problem having receive error message when create class inherits uitabbarcontroller:

application windows expected have root view controller @ end of application launch

in appdelegate class initialise uiviewcontroller , uinavigationcontroller. set rootviewcontroller on uiwindow object use navigation controller this:

var splashcontroller = new splashcontroller(); // uiviewcontroller _navigationcontroller = new uinavigationcontroller(splashcontroller);  ...  _window = new uiwindow(uiscreen.mainscreen.bounds); _window.rootviewcontroller = _navigationcontroller; _window.makekeyandvisible(); 

up until haven't had issue running applications. created new class inherits uitabbarcontroller , error message described above. can post code if needs i've tried running application empty class inherits uitabbarcontroller , still receive same error message.

even if class never gets called in code through commenting out or deleting pushviewcontroller call still can't run application.

the call tab bar controller this:

splashcontroller (uiviewcontroller) > push > homecontroller (uiviewcontroller) > push > menucontroller (dialogviewcontroller) > push > statscontroller (uitabbarcontroller) 

i'm guessing there's missing here after googling , searching around couldn't find answer problem. help

if using uitabbarcontroller should this:

window = new uiwindow (uiscreen.mainscreen.bounds);              var viewcontroller1 = new firstviewcontroller ();             var viewcontroller2 = new secondviewcontroller ();              tabbarcontroller = new uitabbarcontroller ();             tabbarcontroller.viewcontrollers = new uiviewcontroller [] {                 viewcontroller1,                 viewcontroller2,             };              window.rootviewcontroller = tabbarcontroller;             window.makekeyandvisible (); 

the uitabbarcontroller should rootviewcontroller.