How to end/remove the Cocos2D animation from UIView?

Question

The Cocos2D version is 2.1.

I add a Cocos2D animation to my UIView while searching. After finish searching, I remove the director's view from my UIView:

- (void)didFinishSearchAnimation
{
    CCDirectorIOS *director = self.director;
    [director.view removeFromSuperview];
    self.director = nil;
    _isSearching = NO;    
}

The Cocos2D view did be removed from superview.

But when next time I press the search button and try to show the Cocos2D animation on my UIView, the CCGLView become purple, and the console shows OpenGL error 0x0502 in -[CCSprite draw] 530.

I don't know what happened and how to fix it.

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By the way, how to change the background of scene/view of the CCDirectorIOS to transparent for showing the UIView behind them?