title: NetBeans GUI builder: "loading..." message
body: <p>Sample project from the NetBeans tutorials set contains only one Swing form (empty JFrame), compiles and runs fine, but I can't change layout of the form and add elements in it with the NetBeans GUI buider since it shows only empty placeholder with single "loading..." message. Any clues how to fix it would be highly appreciated.</p>
  
  <p>Kubuntu 12.04, Openjdk 1.7, NetBeans 7.0.1 with active GUI designer plugin.</p>
  
  <p>Log file contains an error </p>
  
  <p><code>SEVERE [org.openide.util.RequestProcessor]: Error in RequestProcessor org.netbeans.modules.form.FormDesigner$PreLoadTask</code> </p>