SQL Error: ORA-14048: a partition maintenance operation may not be combined with other operations

We are on Oracle database 11.2.0.2...We are doing a mass insert in a table and so we thought to make the indexes unusable..While doing it, we got this error -

-- 11.48.39 ..(Z_STMT_EXTR.PRELOAD.DROP-IND) (SQL) ALTER INDEX anicap.AZ_PASSV_TAO9 UNUSABLE; /

-- Row(s) affected: 0

-- 11.48.39 Process 16960584 ABENDED at Step D_SMT_EXT.LOAD.DROP-USA (Action SQL) -- RC = 18048 ROLLBACK /

-- 11.39.42 SQL Error: ORA-14048: a partition maintenance operation may not be combined with other operations

The table has no partitions -

select partitioned FROM DBA_indexes WHERE TABLE_NAME='AZ_PASSV_TAO9'

PARTITION

---------

NO

NO