Localisation error on configuration.

On the Localisation configuration screen - http://example.com/civicrm/admin/setting/localization?reset=1&civicrmDestination=%2Fcivicrm%2Fadmin%2Fconfigtask%3Freset%3D1 it states in the section entitled "Contact Address Fields - Selection Values" for the 'Available Countries' field : "To include ALL countries, leave the right-hand box empty."
However, if the user leaves the right hand box empty this generates an error message (see attached screenshot). This used to work as advertised in previous versions. The workaround is to move all countries into the right hand box.