crash when launching the application

i have made a UIViewController (LoadingViewController) which is the first view to be displayed after the didFinishLaunching and it will hold a UIProgressView later, and then the user is redirected to the MenuView (MenuViewController), however i have got crash when i build and run the application :

2011-05-07 23:03:29.673 MyApp[2442:207] *** Terminating app due to uncaught exception 'NSUnknownKeyException', reason: '[<MyAppAppDelegate 0x6b4e550> setValue:forUndefinedKey:]: this class is not key value coding-compliant for the key viewController.'
    *** Call stack at first throw:
    (
        0   CoreFoundation                      0x0291d919 __exceptionPreprocess + 185
        1   libobjc.A.dylib                     0x027325de objc_exception_throw + 47
        2   CoreFoundation                      0x0291d851 -[NSException raise] + 17
        3   Foundation                          0x000acc2b _NSSetUsingKeyValueSetter + 135
        4   Foundation                          0x000acb99 -[NSObject(NSKeyValueCoding) setValue:forKey:] + 285
        5   UIKit                               0x00526d0a -[UIRuntimeOutletConnection connect] + 112
        6   CoreFoundation                      0x02893b6f -[NSArray makeObjectsPerformSelector:] + 239
        7   UIKit                               0x00525721 -[UINib instantiateWithOwner:options:] + 1041
        8   UIKit                               0x005274b5 -[NSBundle(UINSBundleAdditions) loadNibNamed:owner:options:] + 168
        9   UIKit                               0x003369bb -[UIApplication _loadMainNibFile] + 172
        10  UIKit                               0x0033790d -[UIApplication _runWithURL:payload:launchOrientation:statusBarStyle:statusBarHidden:] + 198
        11  UIKit                               0x00341452 -[UIApplication handleEvent:withNewEvent:] + 1958
        12  UIKit                               0x0033a074 -[UIApplication sendEvent:] + 71
        13  UIKit                               0x0033eac4 _UIApplicationHandleEvent + 7495
        14  GraphicsServices                    0x02e97afa PurpleEventCallback + 1578
        15  CoreFoundation                      0x028fedc4 __CFRUNLOOP_IS_CALLING_OUT_TO_A_SOURCE1_PERFORM_FUNCTION__ + 52
        16  CoreFoundation                      0x0285f737 __CFRunLoopDoSource1 + 215
        17  CoreFoundation                      0x0285c9c3 __CFRunLoopRun + 979
        18  CoreFoundation                      0x0285c280 CFRunLoopRunSpecific + 208
        19  CoreFoundation                      0x0285c1a1 CFRunLoopRunInMode + 97
        20  UIKit                               0x00337226 -[UIApplication _run] + 625
        21  UIKit                               0x00342b58 UIApplicationMain + 1160
        22  MyApp                          0x00002d10 main + 102
        23  MyApp                          0x00002ca1 start + 53
    )
    terminate called after throwing an instance of 'NSException'

the stack show that the reason is from MyAppAppDelegate file. here is my relevant code : LoadingViewController.h :

#import <UIKit/UIKit.h>
#import "MenuViewController.h"

@interface LoadingViewController : UIViewController {

IBOutlet MenuViewViewController *menuViewController;

}
@end

LoadingViewController.m :
#import "LoadingViewController.h"
@implementation LoadingViewController

- (void)viewDidLoad {
    [super viewDidLoad];
}


- (void)dealloc {
    [super dealloc];
}
@end

the MyAppAppDelegate.h :

#import <UIKit/UIKit.h>
@class LoadingViewController;
@interface MyAppAppDelegate : NSObject <UIApplicationDelegate,CLLocationManagerDelegate> {
    UIWindow *window;
        LoadingViewController *loadingView;
}
@property (nonatomic, retain) IBOutlet UIWindow *window;
@prop开发者_开发百科erty (nonatomic, retain) IBOutlet LoadingViewController *loadingView;
@end

the MyAppAppDelegate.m :

    #import "MyAppAppDelegate.h"
    #import "LoadingViewController.h"
    @implementation MyAppAppDelegate
    @synthesize window;

    @synthesize loadingView;


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

    [window addSubview:loadingView.view];

    [window makeKeyAndVisible];
    return YES;
}


    - (void)dealloc {

        [loadingView release];
        [window release];
        [super dealloc];
    }
    @end

thx in advance for the help :)

I don't think you posted the relevant code. You only include the dealloc methods and you say it crashes on startup, so the code you posted is never run.

2011-05-07 23:03:29.673 MyApp[2442:207] *** Terminating app due to uncaught exception 'NSUnknownKeyException', reason: '[<MyAppAppDelegate 0x6b4e550> setValue:forUndefinedKey:]: this class is not key value coding-compliant for the key viewController.'

Judging from the thrown exception it seems like you're using an invalid key, namely viewController, to set a value on your app delegate. The problem as far as I can tell is that you haven't declared a viewController property.