title: Can't add constraints in xib
body: <p>I have a xib but I can't add constraints. When I control click and drag I can't do anything also the buttons at the bottom I can't do anything with it.</p>
  
  <p>I'm using xCode 11.</p>
  
  <p><a href="https://i.stack.imgur.com/WylUB.png" rel="noreferrer"><img src="https://i.stack.imgur.com/WylUB.png" alt="enter image description here"></a></p>