Oracle Message ORA-14630 - subpartition resides in offlined tablespace

ERRORsubpartition resides in offlined tablespace
CAUSEUser attempted an operation requiring that we access data in a subpartition which resides in a tablespace which was taken offline. Such operations include trying to drop a tablespace of a table which has indices defined on it or is referenced by a constraint.
ACTIONBring tablespace online before attempting the operation.