title: Stack Empty Exception
body: <p>I am getting a stack empty exception. How is that possible if the stack is not empty (it has 16 items)?</p>
  
  <p>I got a snap shot of the error:</p>
  
  <p><img src="https://i.stack.imgur.com/HWISR.png" alt="Stack Empty Exception"></p>
  
  <p>Can someone please explain?</p>