title: Tab Bar Controller Fully Grey with Xcode 8
body: <p><a href="https://i.stack.imgur.com/SZTrO.png" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/SZTrO.png" alt="enter image description here"></a></p>
  
  <p>I recently made a Single View app. I have a login and sign up screen working w/ Firebase. However, everything was working until I decided to create a <strong>Tab Bar Controller</strong> into the user interface. It doesn't work due to this <strong>allover</strong> <strong>grey</strong> color! I absolutely can't remove it... Does anyone of you know how to fix this issue?</p>