runAction时，Sprite工具包在iOS7.1中崩溃

Question

- (void)viewDidLoad {
  //  self.SCREEN=[[UIScreen mainScreen]bounds];
    [super viewDidLoad];

    NSString *path = [[NSBundle mainBundle] pathForResource:@"MainScene" ofType:@"sks"];

    self.skScene = [NSKeyedUnarchiver unarchiveObjectWithFile:path];

    [self.skView presentScene:self.skScene];

    self.skScene.scaleMode=SKSceneScaleModeAspectFill;

    self.face=(SKSpriteNode*)[self.skView.scene childNodeWithName:@"face_layer"];
    [self.face runAction:[SKAction rotateToAngle:30 duration:0]];
}

face是场景中的SKSpriteNode，但是此代码总是在iOS7.1中崩溃，在8.0或8.1中运行。

0xd1b34c:  movl   $0x0, 0x28(%ecx)
0xd1b353:  cmpb   $0x0, 0xc(%ecx)
0xd1b357:  je     0xd1b364                  ; SKCAction::willStartWithTargetAtTime(SKCSprite*, double) + 46
0xd1b359:  movl   (%ecx), %eax
0xd1b35b:  movl   0x28(%eax), %eax      Thread1:EXC_BAD_ACCESS(code=1,address=0x36...)
0xd1b35e:  addl   $0x18, %esp
0xd1b361:  popl   %ebp
0xd1b362:  jmpl   *%eax

是iOS7.1的错误吗？感谢