The values in the row are not available for this trigger

  Explanation:  You tried to refer to the values in the row that
  was changed in a trigger action.  The values are not available
  in an action if action does not specify FOR EACH ROW or is
  triggered at a time when values are not supported.

  User Action:  Rewrite your trigger so that values are available
  or there are no references to the values.