illegal thresholds usage - area <str> exists,  and  cannot  have
  THRESHOLDS respecified

  Explanation:  You cannot  redefine  thresholds  on  an  existing
  area.

  User Action:  Delete and recreate  the  area  with  the  desired
  thresholds  or  create  an area with the new thresholds and move
  the data from the old to the new area.