partition "<str>" has no following partition in  map  "<str>"  -
  drop not allowed

  Explanation:  You  performed  a  DROP  PARTITION  on  the  final
  partition of an an index or storage map.  DROP wants to migrates
  the data to the next partition in the map, but can not  if  this
  is the last partition.

  User Action:  Use MOVE to move the data to another partition, or
  DROP INDEX or DROP STORAGE MAP to remove the partition.