title: Eclipse Mars - The currently displayed page contains invalid values
body: <p>I'm using Eclipse and was experimenting with WebDriver, DBunit, Maven and the likes.  One fine moment I needed to add a Reference Library (right click project > Properties > Java Build Path), and I'm suddenly getting the error "The currently displayed page contains invalid values." :(</p>
  
  <p>Any ideas? I've already re-installed Eclipse and re-instated my workspace but the problem occurred again.</p>