title: Xcode: Interface Builder XIB Compiler Error
body: <p>Xcode 5.1.1 and OS X 10.9.3</p>
  
  <p>I open Xcode and start a new Cocoa project. I then click run. The build fails, and I get the following error message:</p>
  
  <pre><code>Interface Builder XIB Compiler Error
  Interface Builder was unable to determine the type of "MainMenu.xib".
  </code></pre>
  
  <p>I also don't see the usual WYSIWYG editor when I select <code>MainMenu.xib</code> just a black screen. I notice the "type" of file is "Default - Abstract Interface Builder File", whereas on other working projects I have built in the past, the "type" is "Default - Interface Builder File". Seems there's something about it being an "abstract" file that's causing Xcode to not display the interface builder.</p>
  
  <p>I tried fully uninstalling Xcode and re-downloading it from the App Store. Didn't help. Multiple google searches have turned up nothing helpful, and the other Stack Overflow questions with a similar title to mine aren't illuminating. I can't imagine everyone else with Xcode 5.1 has this issue. Any experts out there that could suggest a quick fix? </p>
  
  <p><img src="https://i.stack.imgur.com/ky474.jpg" alt="enter image description here">
  <img src="https://i.stack.imgur.com/i81Tt.jpg" alt="enter image description here">
  <img src="https://i.stack.imgur.com/McsPT.jpg" alt="enter image description here">
  <img src="https://i.stack.imgur.com/stnH8.jpg" alt="enter image description here"></p>