title: UIButton is not working/Clickable in UIScrollView
body: <p>I am using auto layout with <code>UIScrollView</code>.</p>
  
  <p>Main <code>UIView</code> Height = 1300</p>
  
  <p>ContentView (within <code>UIScrollBar</code>) <code>UIView</code> = 1100</p>
  
  <p>The ConetntView contains a button at the bottom. It is completely visible but when I click it, it does not work.</p>
  
  <p>Constraints are :</p>
  
  <p>1) <code>ScrollView</code> leading, trailing, top &amp; bottom with main <code>UIView</code></p>
  
  <p>2) <code>ContantView</code> leading, trailing, top &amp; bottom with <code>UIScrollView</code></p>
  
  <p>3) Equal height constraint between <code>ContentView</code> &amp; main <code>UIView</code> </p>
  
  <p>Please help.</p>