Applications are expected to have a root view controller at the end of application launch

Question

I get the following error in my console      Applications are expected to have a root view controller at the end of application launch   Below is my application didFinishLaunchWithOptions method   -  BOOL application  UIApplication   application didFinishLaunchingWithOptions  NSDictionary   launchOptions           Set Background Color Pattern     self window backgroundColor    UIColor blackColor       self tabBarController tabBar backgroundColor    UIColor clearColor         self window backgroundColor    UIColor colorWithPatternImage  UIImage imageNamed   testbg png             Set StatusBar Color       UIApplication sharedApplication  setStatusBarStyle UIStatusBarStyleBlackTranslucent           Add the tab bar controller s current view as a subview of the window     self window rootViewController   self tabBarController       self window makeKeyAndVisible       return YES      In Interface Builder  the UITabBarController s delegate is hooked up to the App Delegate    Anyone know how to fix this issue

User · Answer

I had the same error when trying to change the first view controller that was loaded in

- (BOOL)application:(UIApplication *)application didFinishLaunchingWithOptions:(NSDictionary *)launchOptions

At first I didn't really know where the error was coming from precisely so I narrowed it down and found out what went wrong. It turns out that I was trying to change the display of a view before it actually came on screen. The solution was hence to move this code in the viewcontroller that was giving me trouble from

- (void)viewDidLoad

to

- (void)viewDidAppear:(BOOL)animated

and the error stopped appearing. My problem specifically was caused by making a UIAlertView show.

In your case I suggest you check out the code in the tabBarController's active view controller (as it is probably a problem in that view controller). If that doesn't work, try to set the starting settings in the nib file instead of in code - or if you want to do it in code, try moving the code to the tabBarController's active viewcontroller's appropriate method.

Good luck!

User · Answer

Sounds like self tabBarController is returning nil   tabBarController probably is not wired up in Interface Builder   Set the IBOutlet of tabBarController to the tabBarController in Interface Builder

User · Answer

Moving setRootViewController  from didFinishLaunchingWithOptions  to awakeFromNib  solved this in my empty project

User · Answer

There was a slight change around iOS 5 0 or so  requiring you to have a root view controller   If your code is based off older sample code  such as GLES2Sample  then no root view controller was created in those code samples   To fix  that GLES2Sample  for instance   right in applicationDidFinishLaunching  I create a root view controller and attach my glView to it   -  void  applicationDidFinishLaunching  UIApplication   application        To make the  Application windows are expected      to have a root view controller      at the end of application launch  warning go away       you should have a rootviewcontroller       but this app doesn t have one at all    window rootViewController     UIViewController alloc  init       MAKE ONE   window rootViewController view   glView     MUST SET THIS UP OTHERWISE      THE ROOTVIEWCONTROLLER SEEMS TO INTERCEPT TOUCH EVENTS     That makes the warning go away  and doesn t really affect your app otherwise

User · Answer

Validate your STORYBOARD file    If you are using IB to  wire  code to your UI   and just happen to delete the UI element     and then realize  oh you need to delete the reference in the code  in my case a UIButton called AbortButton     then moments later the app won t launch     The issue is in the  storyboard  file  Open it in an xml editor and look for orphaned  relationships   of connectors which point places where they should not     eg    lt relationships gt       lt relationship kind  outlet  name  AbortButton  candidateClass  UIButton   gt   did NOT exist in my code anymore     yet i still had a  connector  linked up in the storyboard file     Also i had  somehow and invalid connector from a UIImageView or a ToolBar to my main UIViewController view object     don t think it liked that either     bottom line - one doesn t have to manually  code the controller  back into existence    the STORYBOARD file is whacked  I fixed mine  and bingo worked perfect again    and BTW  as a text coder   i am growing very fond of IB    kicks butt over MS Visual Studio s IDE

User · Answer

Replace in AppDelegate    window addSubview  someController view      to     self window setRootViewController someController

User · Answer

None of the answer quite fixed my issue   I am working on an old iOS4 project upgraded to ARC and now being worked on in Xcode 5 for iOS 7  I read through all of them and started checking my config and code   What fixed it for me was adding   - BOOL  application  UIApplication   application didFinishLaunchingWithOptions   NSDictionary   launchOptions          Maybe do something     return YES      In addition to having   -  void applicationDidFinishLaunching  UIApplication   application       I did not have   - BOOL  application  UIApplication   application didFinishLaunchingWithOptions   NSDictionary   launchOptions   prior to getting the error

User · Answer

In my case  everything about the actual window and the didFinishLaunchingWithOptions  method was fine   My error was that I didn t realize applicationDidBecomeActive  runs on startup in addition to when the app is coming to the foreground after having been in the background   Therefore  in applicationDidBecomeActive  I was manipulating view controllers that hadn t finished all their setup yet  waiting for different threads to respond  etc    Once I moved this functionality outside of applicationDidBecomeActive  the errors went away

User · Answer

I got this when starting with the  Empty Application  template and then manually adding a XIB   I solved it by setting the main Nib name as suggested by Sunny  The missing step in this scenario is removing  self window      UIWindow alloc  initWithFrame   UIScreen mainScreen  bounds   autorelease     from  application  UIApplication   application didFinishLaunchingWithOptions  NSDictionary   launchOptions   As it will overwrite the instance of your window created in the Xib file  This is assuming you have created a ViewController and wired it up with your window and App Delegate in the XIB file as well

User · Answer

With my first view being MenuViewController I added   MenuViewController  menuViewController     MenuViewController alloc init   self window rootViewController   menuViewController    on the App Delegate method   -  BOOL application  UIApplication   application didFinishLaunchingWithOptions  NSDictionary   launchOptions       That worked

User · Answer

This error also show up when file s owner of MainWindow xib is set incorrectly   File s owner is UIApplication- inserted object of app delegate class with window outlet connected to window

User · Answer

I began having this same issue right after upgrading to Xcode 4 3  and only when starting a project from scratch  i e  create empty project  then create a UIViewController  and then Create a separate nib file     After putting ALL the lines I used to  and ensuring I had the correct connections  I kept getting that error  and the nib file I was trying to load through the view controller  which was set as the rootController  never showed in the simulator   I created a single view template through Xcode and compared it to my code and FINALLY found the problem   Xcode 4 3 appears to add by default the method - void loadView  to the view controller implementation section  After carefully reading the comments inside it  it became clear what the problem was  The comment indicated to override loadView method if creating a view programmatically  and I m paraphrasing   otherwise NOT to override loadView if using a nib  There was nothing else inside this method  so in affect I was overriding the method  and doing nothing  WHILE using a nib file  which gave the error   The SOLUTION was to either completely remove the loadView method from the implementation section  or to call the parent method by adding  super loadView    Removing it would be best if using a NIB file as adding any other code will in effect override it

User · Answer

I ran into this in an iPad application targeting iOS 5 1 in Xcode 4 5 1  The app uses UITabBarController  I needed a new section within the tab bar controller  so I created a new view controller and xib  Once I added the new view controller to the tab bar controller  none of my on-screen controls worked anymore  and I got the  expected to have a root view controller  log   Somehow the top-level object in the new xib was UIWindow instead of UIView  When I dropped a UIView into the XIB  had the view outlet point to it  moved all the subviews into the new UIView  and removed the UIWindow instance  the problem was fixed

User · Answer

Although a lot of these answers seem valid  none of them fixed the message for me   I was experimenting with the empty application template and trying to load straight to a  xib file for understanding sake  like to old window template    It seems like Apple left an NSLog message running     I was on Xcode 4 3 and nothing seemed to get rid of the message and I wanted to know why   Finally I decided to see what would happen in Xcode 4 5  preview iPhone 6 0 build  and the message is no longer there   Moving on

User · Answer

On top of  sho  answer  that is correct  fourth parameter of UIApplicationMain should be the name of the main controller   I add some comments   I have recently changed the  model  of an app of mine from using MainWindow xib to construct a window programatically  The app used an older template that created that MainWindow automatically  Since I wanted to support a different controller view XIB for iPhone 5  it is easier to choose the right XIB programatically when the App Delegate is created  I removed MainWindow xib from project as well   Problem was  I forgot to fill the fourth parameter in UIApplication main and I FORGOT TO REMOVE MainWindow from  Main Interface  at Project Summary   This caused a BIG problem  it rendered the harmless warning  Applications are expected to     on development devices  but when it went to App Store  it broke on consumer phones  crashing because MainWindow was no longer in the bundle  I had to request an expedited review for the bugfix   Another sympthom is that sometimes a white block  like a blank UIView  was sometimes appearing when Settings were changed and app was put in foreground  In iPhone 5 it was clear that it was an 320x480 block  Perhaps the missing MainWindow was being created in development mode  using the old size  I had just found this bug when the first reports of the crash reached the inbox   Installing the app from App Store instead of from XCode showed that the app indeed crashed  and the MainWindow issue revealed itself on log  so I could see that it was not some special combination of devices IOS versions

User · Answer

how to add a RootViewController for iOS5  if your app didn t use a RootViewController till now  just create one    by hitting File   New   New File  select UIViewController subclass name it RootViewController  uncheck the With XIB for user interface  assuming you already have one  and put this code in your AppDelegate    didFinishLaunchingWithOptions  rootViewController     RootViewController alloc  init   window rootViewController   rootViewController    for sure - you have to import RootViewController h and create the variable  here is a nice article about the RootViewController and the AppDelegate

User · Answer

This issue happens when you don t have Interface Builder set up correctly   Ensure your App Delegate s window and viewController outlets are hooked up   In your MainWindow xib  hold control  click App Delegate and drag to the Window object  Select window  Hold control and select the App delegate again  drag to your root view controller and select viewController

User · Answer

Select your  Window  in your Nib File In  Attributes Inspector  Check  Visible at Launch       This happens when your nib file is created manually  This fix works for regular nib mode - not storyboard mode

User · Answer

for ARC change   change to    synthesize window    instead of    synthesize window  window

User · Answer

I had this error too but no answer already listed was solving my issue  In my case the log display was due to the fact I was assigning the application root view controller in another sub-thread   - BOOL  application  UIApplication   application didFinishLaunchingWithOptions  NSDictionary   launchOptions               dispatch queue t queue   dispatch get global queue DISPATCH QUEUE PRIORITY DEFAULT  0       dispatch async queue                         dispatch async dispatch get main queue                                    self updateTabBarTitles               self window rootViewController   self tabBarController                                            self window makeKeyAndVisible       return YES      By moving the rootViewController assignment to the end of the function - just before the call to makeKeyAndVisible  - causes the log message not to be displayed again                 self window rootViewController   self tabBarController       self window makeKeyAndVisible       return YES      I hope this helps

User · Answer

Make sure you have this function in your application delegate   -  BOOL application  UIApplication   application didFinishLaunchingWithOptions      NSDictionary   launchOptions      return YES      Make sure didFinishLaunchingWithOptions returns YES  If you happened to remove the  return YES  line  this will cause the error    This error may be especially common with storyboard users

User · Answer

I had the same problem  If you re building a window-based application  from scratch  as I was  you ll need to do the following   note  these are steps for Xcode 4 2    0  Make sure your application delegate conforms to the UIApplicationDelegate protocol   For example  suppose our delegate is called MyAppDelegate  In MyAppDelegate h  we should have something like this    interface MyAppDelegate        NSObject  lt UIApplicationDelegate gt     etc     1  Specify the application delegate in main m  For example    import  MyAppDelegate h   int main int argc  char  argv         autoreleasepool       return UIApplicationMain argc  argv        nil  NSStringFromClass  MyAppDelegate class            2  Create a main window interface file   To do this  right-click on your project and choose New File  From there  choose Window from the iOS -  User Interface section   After adding the file to your project  go to the project s summary  left-click on the project  click summary   Under iPhone iPod Deployment Info  and the corresponding iPad section if you like  and select your new interface file in the  Main Interface  combo box   3  Hook it all up in the interface editor  Select your interface file in the files list to bring up the interface editor    Make sure the Utilities pane is open   Add a new Object by dragging an Object from the Objects list in the Utilities pane to the space above of below your Window object  Select the object  Click on the Identity inspector in the Utilities pane  Change the Class to the application s delegate  MyAppDelegate  in this example    Bring up the connections inspector for MyAppDelegate  Connect the window outlet to the Window that already exists in the interface file   Click on File s Owner on the left  and then click on the Identity inspector in the Utilities pane  Change the Class to UIApplication  Bring up the connections inspector for File s Owner  Connect the delegate outlet to the MyAppDelegate object   4  Finally  and very importantly  click on the Window object in the interface file  Open the Attributes inspector  Make sure  Visible at Launch  is checked   That s all I had to do to get it working for me  Good luck

User · Answer

Received the same error after replacing my UI with a Storyboard  using XCode 4 6 3 and iOS 6 1  Solved it by clearing out all of the code from didFinishLaucnhingWithOptions in the AppDelegate  -  BOOL application  UIApplication   application didFinishLaunchingWithOptions  NSDictionary   launchOptions       return YES

User · Answer

I was getting this error  Applications are expected to have a root view controller at the end of application launch   and I was creating the view controllers programmatically   Solved it by ensuring the loadView method in my root view controller was calling  super loadView

User · Answer

To add to Mike Flynn s answer  since upgrading to Xcode 7 and running my app on an iOS 9 device  I added this to my  BOOL application  UIApplication   application didFinishLaunchingWithOptions  NSDictionary   launchOptions     Hide any window that isn t the main window NSArray  windows     UIApplication sharedApplication  windows   for  UIWindow  window in windows        if  window    self window            window hidden   YES

User · Answer

I came across the same issue but I was using storyboard  Assigning my storyboard InitialViewController to my window s rootViewController   In  -  BOOL application  UIApplication   application didFinishLaunchingWithOptions  NSDictionary   launchOptions      UIStoryboard  stb    UIStoryboard storyboardWithName   myStoryboard  bundle nil   self window rootViewController    stb instantiateInitialViewController   return YES      and this solved the issue

User · Answer

This error hit me all of a sudden  So  what caused it    It turns out I was in IB attaching File Owner to a new small ImageView I d dragged onto the View  I hadn t called it an IBOutlet in the  h file  so when I ctrl-dragged to it  the new Imageview wasn t listed as a possible connection  The only possibility displayed in the little black box was View  I must have clicked  inadvertently  I made a few changes then ran the program and got the Root Controller error  The fix was reconnecting File Owner to the bottom View in the xib - IB screen

User · Answer

I also had this problem  Turns out it was when I deleted the App Delegate from the Objects list on the left I deleted the connection for App Delegate  Window and TabBarController

User · Answer

I had the same error message because I called an alert in   -  void applicationDidBecomeActive  UIApplication   application    instead of   -  void applicationWillEnterForeground  UIApplication   application

User · Answer

I run into the same problem recently  when building a project with ios5 sdk  At first it was building and running properly  but after that the error appeared   In my case the solution was rather simple   What was missing  was that somehow the Main Interface  property in the summary tab of my application target got erased  So I needed to set it again    If this is not the point  and if the tabBarController is still nil  you can always programmatically create your window and root controller   As a fallback I added the following code to my project  -  BOOL application  UIApplication   application didFinishLaunchingWithOptions  NSDictionary   launchOptions        if   window  amp  amp   navigationController            NSLog   Window and navigation controller not loaded from nib  Will be created programatically             self window      UIWindow alloc  initWithFrame   UIScreen mainScreen  bounds   autorelease           UIViewController  viewController1   viewController2          viewController1      FirstViewController alloc  initWithNibName   FirstViewController iPhone  bundle nil  autorelease           viewController2      SecondViewController alloc  initWithNibName   SecondViewController iPhone  bundle nil  autorelease            self tabBarController      UITabBarController alloc  init  autorelease           self tabBarController viewControllers    NSArray arrayWithObjects viewController1  viewController2  nil           self window rootViewController   self tabBarController             else            window addSubview  tabBarController view               self window makeKeyAndVisible       return YES      This will work only if sho s solution is implemented also

User · Answer

I also had this error but unlike any of the answers previously listed mine was because i had uncommented the method  loadView  in my newly generated controller  xcode 4 2  ios5       Implement loadView to create a view hierarchy programmatically  without using a nib  -  void loadView         It even told me that the method was for creating the view programmatically but i missed it because it looked so similar to other methods like viewDidLoad that i normally use i didn t catch it    To solve simply remove that method if you are not programmatically creating the view hierarchy aka using nib or storyboard

User · Answer

None of the above suggestions solved my problem  Mine was this   Add   window rootViewController   navigationController    after    window addSubview navigationController view     in my appdelegate s  -  void applicationDidFinishLaunching  UIApplication   application

User · Answer

Have you tried setting the delegate  i e   self rootController delegate   self    within applicationDidFinishLaunchingWithOptions  That worked for me  although I m not sure why

User · Answer

Make sure that your  Is Initial View Controller  is correctly set for your first scene   That s what s causing the error

User · Answer

I was migrating an old EAGLView sample project to the new GLKView sample project in Xcode 4 and none of the solutions worked for me   Finally I realized that I was trying to set the main GLKViewController s self view to point to a nested GLKView in Interface Builder   When I pointed the self view back to the root GLKView in Interface Builder  my app was then able to launch without an error message  so make sure your view controller s view is set to the root view    P S  if you want to get a nested GLKView working  create a new member variable like self glkSubview in ViewController h and drag its connection to the nested GLKView in Interface Builder   Then make sure to drag self glkSubview s delegate to File s Owner   You must manually call  self glkSubview display  in  -  void glkView  GLKView   view drawInRect  CGRect rect  if you have setNeedsDisplay turned off for the GLKView

User · Answer

This happened to me  Solved by editing  plist file  Specify the Main nib file base name  Should be MainWindow xib   Hope this will help

User · Answer

I upgraded to iOS9 and started getting this error out of nowhere   I was able to fix it but adding the below code to -  BOOL application  UIApplication   application didFinishLaunchingWithOptions  NSDictionary   launchOptions  NSArray  windows     UIApplication sharedApplication  windows   for UIWindow  window in windows        if window rootViewController    nil           UIViewController  vc     UIViewController alloc initWithNibName nil bundle nil           window rootViewController   vc

User · Answer

i got this problems too  i got my project run in xcode4 2 1  i ve read all comments up there  but no one is cool for me  after a while  i find that i commented a piece of code     self window      UIWindow alloc  initWithFrame   UIScreen mainScreen  bounds   autorelease     then i uncommented it  everything is ok for me  hope this would helpful for you guys

User · Answer

OrdoDei gave a correct and valuable answer  I m adding this answer only to give an example of a didFinishLaunchingWithOptions method that uses his answer as well as accounting for the others    comments regarding Navigation Controller   -  BOOL application  UIApplication   application didFinishLaunchingWithOptions  NSDictionary   launchOptions       self window     UIWindow alloc  initWithFrame   UIScreen mainScreen  bounds            Override point for customization after application launch          Instantiate the main menu view controller  UITableView with menu items          Pass that view controller to the nav controller as the root of the nav stack         This nav stack drives our  entire  app      UIViewController  viewController     XMMainMenuTableViewController alloc  init       self navigationController     UINavigationController alloc  initWithRootViewController viewController           Instantiate the app s window  Then get the nav controller s view into that window  and onto the screen      self window     UIWindow alloc  initWithFrame   UIScreen mainScreen  bounds            self window addSubview self navigationController view          The disabled line above was replaced by line below  Fixed Apple s complaint in log  Application windows are expected to have a root view controller at the end of application launch      self window setRootViewController self navigationController       self window backgroundColor    UIColor whiteColor        self window makeKeyAndVisible       return YES

User · Answer

I had this same problem   Check your main m   The last argument should be set to the name of the class that implements the UIApplicationDelegate protocol   retVal   UIApplicationMain argc  argv  nil    AppDelegate

User · Answer

I had this same error message in the log  I had a UIAlertView pop up in application didFinishLaunchingWithOptions  I solved it by delaying the call to the alertView to allow time for the root view controller to finishing loading   In application didFinishLaunchingWithOptions    self performSelector  selector callPopUp  withObject nil afterDelay 1 0     which calls after 1 second   -  void callPopUp          call UIAlertView

User · Answer

I solved the problem by doing the following  none of the other solutions above helped    From the pulldown menu associated with  Main Interface  select another entry and then reselect  MainWindow  then rebuild

User · Answer

None of the above worked for me    found out something wrong with my init method on my appDelegate  If you are implementing the init method make sure you do it correctly  i had this   -  id init       if   self            self    super init           sharedInstance   self            return sharedInstance      and changed it to this   -  id init       if   self            self    super init             sharedInstance   self      return sharedInstance      where  sharedInstance  its a pointer to my appDelegate singleton

User · Answer

I was able to set the initial view controller on the summary screen of xcode   Click on the top most project name in the left hand file explorer  it should have a little blueprint icon   In the center column click on your project name under  TARGETS    it should have a little pencil  A  icon next to it   Look under  iPhone   iPod Deployment Info  and look for  Main Interface   You should be able to select an option from the drop down

User · Answer

If your app replaces the main UIWindow with FingerTipWindow  to show touches on a projector  and you haven t updated your sources for a few  several  years  your replacement object might not include a rootViewController property  see kgn s 5 21 2013 mod at GitHub    You can set window rootViewController in didFinishLaunchingWithOptions until the cows come home  but your window will not report one  at end of application launch  and will throw an exception at runtime  Update your sources

User · Answer

Try to connect IBOutlet of tab bar controller to root view in the Interface Builder instead of  self window rootViewController   self tabBarController    But actually I haven t seen such error before

User · Answer

This Swift 2 solution worked for me    Insert the code below in AppDelegate  -   didFinishLaunchingWithOptions  self window  rootViewController   storyboard instantiateViewControllerWithIdentifier  YourRootViewController   as  YourRootViewControllerClass

User · Answer

If you use MTStatusBarOverlay  then you ll get this error   MTStatusBarOverlay creates an additional window    UIApplication sharedApplication  windows  which doesn t have a root controller   This doesn t seem to cause a problem

User · Answer

This occurred for me because i inadvertently commented out    self window makeKeyAndVisible     from  -  BOOL application  UIApplication   didFinishLaunchingWithOptions  NSDictionary

[ios] Applications are expected to have a root view controller at the end of application launch

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