Using the Tab bar results in an iPhone crash

I seem to be having an issue with loading a gam开发者_运维技巧e on a tab in a tab bar application. When I run the app and click on the tab that the game is supposed to go on, it crashes giving me this in console:

2011-03-20 08:36:29.311 ComputerClan[21592:207] *** Terminating app due to uncaught exception 'NSUnknownKeyException', reason: '[<UIViewController 0x6948f30> setValue:forUndefinedKey:]: this class is not key value coding-compliant for the key racquet_green.'
*** Call stack at first throw:
(
    0   CoreFoundation                      0x017ea5a9 __exceptionPreprocess + 185
    1   libobjc.A.dylib                     0x0193e313 objc_exception_throw + 44
    2   CoreFoundation                      0x017ea4e1 -[NSException raise] + 17
    3   Foundation                          0x001a7677 _NSSetUsingKeyValueSetter + 135
    4   Foundation                          0x001a75e5 -[NSObject(NSKeyValueCoding) setValue:forKey:] + 285
    5   UIKit                               0x0062b30c -[UIRuntimeOutletConnection connect] + 112
    6   CoreFoundation                      0x017608cf -[NSArray makeObjectsPerformSelector:] + 239
    7   UIKit                               0x00629d23 -[UINib instantiateWithOwner:options:] + 1041
    8   UIKit                               0x0062bab7 -[NSBundle(UINSBundleAdditions) loadNibNamed:owner:options:] + 168
    9   UIKit                               0x004e1628 -[UIViewController _loadViewFromNibNamed:bundle:] + 70
    10  UIKit                               0x004df134 -[UIViewController loadView] + 120
    11  UIKit                               0x004df00e -[UIViewController view] + 56
    12  UIKit                               0x004dd482 -[UIViewController contentScrollView] + 42
    13  UIKit                               0x004edf25 -[UINavigationController _computeAndApplyScrollContentInsetDeltaForViewController:] + 48
    14  UIKit                               0x004ec555 -[UINavigationController _layoutViewController:] + 43
    15  UIKit                               0x004ed7aa -[UINavigationController _startTransition:fromViewController:toViewController:] + 326
    16  UIKit                               0x004e832a -[UINavigationController _startDeferredTransitionIfNeeded] + 266
    17  UIKit                               0x004ef562 -[UINavigationController pushViewController:transition:forceImmediate:] + 932
    18  UIKit                               0x004e81c4 -[UINavigationController pushViewController:animated:] + 62
    19  UIKit                               0x004f469a -[UIMoreNavigationController pushViewController:animated:] + 105
    20  UIKit                               0x004a6b68 -[UITableView _selectRowAtIndexPath:animated:scrollPosition:notifyDelegate:] + 1140
    21  UIKit                               0x0049cb05 -[UITableView _userSelectRowAtPendingSelectionIndexPath:] + 219
    22  Foundation                          0x001ae79e __NSFireDelayedPerform + 441
    23  CoreFoundation                      0x017cb8c3 __CFRUNLOOP_IS_CALLING_OUT_TO_A_TIMER_CALLBACK_FUNCTION__ + 19
    24  CoreFoundation                      0x017cce74 __CFRunLoopDoTimer + 1220
    25  CoreFoundation                      0x017292c9 __CFRunLoopRun + 1817
    26  CoreFoundation                      0x01728840 CFRunLoopRunSpecific + 208
    27  CoreFoundation                      0x01728761 CFRunLoopRunInMode + 97
    28  GraphicsServices                    0x01dda1c4 GSEventRunModal + 217
    29  GraphicsServices                    0x01dda289 GSEventRun + 115
    30  UIKit                               0x0043dc93 UIApplicationMain + 1160
    31  ComputerClan                        0x00002b02 main + 84
    32  ComputerClan                        0x00002aa5 start + 53
)
terminate called after throwing an instance of 'NSException'

It seems as if you have a problem in the XIB you are trying to load. Make sure there are no invalid connections, i.e. connections to non-existent IBOutlets or IBActions. Also make sure you haven't defined any objects to be non-existent classes.