NSInvocation Error - iphone

Question

So I have been trying to create a menu for a game I have developed.
I am using Cocos2d and the game is set in portrait orientation. The menu.m file that I have written looks like this.
// Import the interfaces
#import "Menu.h"
#import "BankerInfo.h"
// HelloWorldLayer implementation
#implementation MenuLayer
+(CCScene *) scene
{
// 'scene' is an autorelease object.
CCScene *scene = [CCScene node];
// 'layer' is an autorelease object.
MenuLayer *layer = [MenuLayer node];
// add layer as a child to scene
[scene addChild: layer];
// return the scene
return scene;
}
// on "init" you need to initialize your instance
-(id) init
{
// always call "super" init
// Apple recommends to re-assign "self" with the "super" return value
if( (self=[super init])) {
// ask director the the window size
CGSize winSize = [[CCDirector sharedDirector] winSize];
CCSprite *menubackground = [CCSprite spriteWithFile:#"Ninja Menu Background.png"];
menubackground.position = ccp(winSize.width/2, winSize.height/2);
[self addChild:menubackground z:-1];
CCLabelTTF *title = [CCLabelTTF labelWithString:#"Catch It If You Can!" fontName:#"Zapfino" fontSize:22];
title.position = ccp(160, 420);
[self addChild: title];
CCLayer *menuLayer = [[CCLayer alloc] init];
[self addChild:menuLayer];
CCMenuItem *Bankerbutton = [CCMenuItemImage
itemFromNormalImage:#"Bankernotpressed.png"
selectedImage:#"Bankerpressed.png"
target:self
selector:#selector(startBanker:)];
//Bankerbutton.position = ccp(100, 175);
CCMenuItem *Babybutton = [CCMenuItemImage
itemFromNormalImage:#"Babynotpressed.png"
selectedImage:#"Babypressed.png"
target:self
selector:#selector(startBaby:)];
//Babybutton.position = ccp(100, 75);
CCMenuItem *Mommaduckbutton = [CCMenuItemImage
itemFromNormalImage:#"Mommaducknotpressed.png"
selectedImage:#"Mommaduckpressed.png"
target:self
selector:#selector(startMommaduck:)];
//Mommaduckbutton.position = ccp(350, 175);
CCMenuItem *Baseballbutton = [CCMenuItemImage
itemFromNormalImage:#"Baseballnotpressed.png"
selectedImage:#"Baseballpressed.png"
target:self
selector:#selector(startArcher:)];
//Baseballbutton.position = ccp(350, 75);
CCMenuItem *Newtonbutton = [CCMenuItemImage
itemFromNormalImage:#"Newtonnotpressed.png"
selectedImage:#"Newtonpressed.png"
target:self
selector:#selector(startArcher:)];
//Newtonbutton.position = ccp(350, 75);
CCMenu *menu = [CCMenu menuWithItems: Bankerbutton, Babybutton, Mommaduckbutton, Baseballbutton, Newtonbutton, nil];
menu.position = ccp(winSize.width/2, (winSize.height/2)-30);
[menu alignItemsInRows:
[NSNumber numberWithInt:2], [NSNumber numberWithInt:2], nil];
[menuLayer addChild: menu];
}
return self;
}
- (void) startBanker: (id) sender
{
[[CCDirector sharedDirector] replaceScene:[BankerInfoLayer scene]];
}
/*- (void) startBaby: (id) sender
{
[[CCDirector sharedDirector] replaceScene:[Backgroundinfo_Soldier scene]];
}
- (void) startMommaduck: (id) sender
{
[[CCDirector sharedDirector] replaceScene:[Backgroundinfo_Mage scene]];
}
- (void) startBaseball: (id) sender
{
[[CCDirector sharedDirector] replaceScene:[Backgroundinfo_Archer scene]];
}
- (void) startNewton: (id) sender
{
[[CCDirector sharedDirector] replaceScene:[Backgroundinfo_Archer scene]];
}
*/
// on "dealloc" you need to release all your retained objects
- (void) dealloc
{
// in case you have something to dealloc, do it in this method
// in this particular example nothing needs to be released.
// cocos2d will automatically release all the children (Label)
// don't forget to call "super dealloc"
[super dealloc];
}
#end
And the error I'm getting looks like this.
Terminating app due to uncaught exception 'NSInvalidArgumentException',
reason: '+[NSInvocation invocationWithMethodSignature:]:
method signature argument cannot be nil'
Any Ideas?

Answer 1

The error states that thi is happening because of a bad call to an unexisting method signature. If you provide the functions used on the menu creation, does it still crash?
STEP 1: Make sure that the baseball button and newton button direct to the right selector, and not just the "startArcher:" that doesnt exist.
CCMenuItem *Baseballbutton = [CCMenuItemImage
itemFromNormalImage:#"Baseballnotpressed.png"
selectedImage:#"Baseballpressed.png"
target:self
selector:#selector(startBaseball:)]; // CHANGED HERE
//Baseballbutton.position = ccp(350, 75);
CCMenuItem *Newtonbutton = [CCMenuItemImage
itemFromNormalImage:#"Newtonnotpressed.png"
selectedImage:#"Newtonpressed.png"
target:self
selector:#selector(startNewton:)]; // CHANGED HERE
STEP 2: Uncomment the functions so you actually have valid selectors
- (void) startBanker: (id) sender
{
[[CCDirector sharedDirector] replaceScene:[BankerInfoLayer scene]];
}
- (void) startBaby: (id) sender
{
[[CCDirector sharedDirector] replaceScene:[Backgroundinfo_Soldier scene]];
}
- (void) startMommaduck: (id) sender
{
[[CCDirector sharedDirector] replaceScene:[Backgroundinfo_Mage scene]];
}
- (void) startBaseball: (id) sender
{
[[CCDirector sharedDirector] replaceScene:[Backgroundinfo_Archer scene]];
}
- (void) startNewton: (id) sender
{
[[CCDirector sharedDirector] replaceScene:[Backgroundinfo_Archer scene]];
}