title: Can't open windows in Eclipse Juno
body: <p>I just updated to Eclipse Juno from Eclipse Indigo. </p>
  
  <p>When I try to open almost any of the windows with options, like <code>Preferences</code> or <code>Switch workspace</code>, it does nothing. The only ones I've discovered I can open are the <code>Eclipse Marketplace...</code> and <code>Install new software...</code>.</p>
  
  <p>Edit: I just discovered I can access to <code>Preferences</code> through <code>Install new software...</code> then <code>Available Software Sites</code>. </p>