This doesn't seem to affect functionality.
To reproduce (from the smoketest in Go Green, but also occurs in at least testsuite):
- On the dashboard click on "to the documents"
- Click in tree view on triangle before "Hippo Ga Groen" (i.e. the DUTCH version)
- Click in subtree on label "Evenementen"
- Access context menu of "Evenementen"
- Click on "Add new event folder..."
- Type "2006" into name input box
- Click on "Edit" radio link
- Type "twothousandsix" over existing text "2006" in URL name text box
- Use "enter" key to confirm dialog
The complete warning in the cms log is:
2012-08-29 09:25:54,603 WARN [http-8080-7] [org.apache.wicket.request.target.component.listener.BehaviorRequestTarget.processEvents():146] component not enabled or visible; ignoring call. Component: [MarkupContainer [Component id = button]]