title: Content disappeared in Storyboard editor
body: <p>Upon updating to Xcode Beta 7, I noticed that nothing was actually visible in my storyboard files. It currently looks like this (isn't it strange that the segues are all the same length now?)
  <img src="https://i.stack.imgur.com/OZzrb.png" alt="enter image description here"></p>
  
  <p>The views are all grayed out in the menu on the left side as well. That appears as follows:
  <img src="https://i.stack.imgur.com/4hSYG.png" alt="enter image description here"></p>
  
  <p>Also, the views load in the simulator as they did before. All the views are still there. Any thoughts?</p>