Oracle Solution for Error ora-14408

ORA-14408: partitioned index contains subpartitions in a different tablespace

What triggered the Error:

An attempt was made to drop a tablespace which contains indexes whose subpartitions are not completely contained in this tablespace, and which are defined on the tables which are completely contained in this tablespace.

What should we do to fix it:

find indexes with subpartitions which span the tablespace being dropped and some other tablespace(s). Drop these indexes, or move the index partitions to a different tablespace, or find the tables on which the indexes are defined, and drop (or move) them.