title: Using WindowBuilder Pro the design tab is missing several components
body: <p>I'm doing a project using WindowBuilder Pro and all has been fine up until now. When I am in the "design" tab the preview of the GUI and the components view do are missing a lot of the components from my code.</p>
  
  <p>Here my interface when compiled: 
  <img src="https://i.stack.imgur.com/Z3mzU.png" alt="enter image description here">
  As you can see there are several components</p>
  
  <p>And here is the design tab: 
  <img src="https://i.stack.imgur.com/1VX74.png" alt="enter image description here"></p>
  
  <p>All that is shown in the Components section and the Preview section is the Main Tabs component and the components it contains. Just a couple of days ago the components section was fine, it showed all the components that you can see in the first image. What is the problem?</p>
  
  <p>Edit: Just in case anyone's interested, I did some messing around and I have an if-else conditional in my constructor which seems to mess things up - without it everything works ok</p>