Looks like the update wants to add a sef url name: Intern while it already exists. check forum sef table in dbase if that is correct.
Maybe you can go to admin/database check database.. an see if this will mention an error. If yes, maybe it can be fixed.
(alternative method, success ??? > the long way would be (to eliminate) empty the dbase name o from that table only, memorise it, save, run update, and watch outcome.
If corrrected, but name still missing in dbase, add Intern directly back in that table.)