Iphone NSUnknownKeyException面临错误

我是iOS新手，请帮助，当我第一次运行代码时，它在emulator中成功运行，并具有正确的输出。现在，对于相同的代码，它显示以下错误：

2015-10-09 11:25:30.569 ViewController[1417:44846]*终止应用程序 由于未捕获的异常“NSUnknownKeyException”，原因： “[setValue:forUndefinedKey:]：此 类与键outlinebtn的键值编码不兼容。' *第一次抛出调用堆栈：

0 CoreFoundation 0x000000010c840f35 异常预处理+165 1 libobjc.A.dylib 0x000000010c130bb7 objc_异常_抛出+45 2 CoreFoundation 0x000 000 010C840B79- [ NSExpExp] + 9 3基金会 0x000000010bccd7b3-[NSObjectNSKeyValueCoding设置值：forKey:]+ 259 4 CoreFoundation 0x000000010c78ae80 -[NSArray makeObjectsPerformSelector:+224 5 UIKit 0x000000010cef2c7d-[UINib实例化所有者：选项：][1506 UIKit 0x000000010cd51f98 -[UIViewController\u loadViewFromNibNamed:bundle:+242 7 UIKit 0x000000010cd52588-[UIViewController loadView]+109 8 UIKit 0x000000010cd527f9-[UIViewController loadViewIfRequired]+75 9 UIKit 0x000000010cd52c8e -[UIViewController视图]+27 10 UIKit 0x000000010cc71ca9-[UIWindow AddRootViewController可能]+ 58 11 UIKit 0x000000010cc72041 -[UIWindow\u setHidden:强制：+247 12 UIKit 0x000000010cc7e72c-[UIWindow makeKeyAndVisible]+42 13 UIKit 0x000000010cc29061-[UIC]应用程序 _callInitializationDelegatesForMainScene:transitionContext:+2628 14 UIKit 0x000000010cc2bd2c -[UIApplication\u在主场景中运行：transitionContext:completion:+1350 15 UIKit 0x000000010cc2abf2 -[UIApplication WorkspaceDiEndTransaction:+179 16 FrontBoardServices 0x000000010f3e92a3 __31-[FBSSerialQueue performAsync:][U block_invoke+16 17 CoreFoundation 0x000000010c77653c __CFRUNLOOP\u正在调用\u OUT\u到\u块+12 18 CoreFoundation 0x000000010c76c285 \u CFRUNLOOP块+341 19 CoreFoundation 0x000000010c76ba43\uuuu CFRunLoopRun+851 20 CoreFoundation 0x000000010c76b486 CFRunLoopRunSpecific+470 21 UIKit 0x000000010cc2a669-[UIApplication\u run]+413 22 UIKit 0x000000010cc2d420 UIApplicationMain+1282 23视图控制器 0x000000010bc01e43 main+115 24 libdyld.dylib 0x000000010edd0145 start+1 libc++abi.dylib:终止于 NSException lldb类型的未捕获异常

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怎么办？？？/请帮帮我。我是iOS新手

放置断点并确定崩溃线。。。。并将其包括在问题中。可能的副本

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

int main(int argc, char * argv[]) {
    @autoreleasepool {
        return UIApplicationMain(argc, argv, nil, NSStringFromClass([AppDelegate class]));
    }
}