Assertion Failure - SimpleGame Part 2

Been working through the code here (https://github.com/clawoo/SimpleGamePart2Cocos2D-x) which is a port of the tutorial on ray wenderlich’s simple game.

My code is just a copy of the code available at https://github.com/clawoo/SimpleGamePart2Cocos2D-x/blob/master/Classes/HelloWorldScene.cpp

The code builds without any errors, but when I try to run it, I receive an assertion failure error at the finishShoot function:

@
void HelloWorld::finishShoot()
{
this~~>addChild;
*projectiles->addObject;
*nextProjectile~~>release();
_nextProjectile = NULL;
}
@

Anyone face similar issues.
I am running on Windows 7, using VS Express 2010 and cocos2d-x 2.1.0