Oracle Message ORA-26029 - index string.string partition string initially in unusable state

ERRORindex string.string partition string initially in unusable state
CAUSEA partition of an index is in IU state prior to the beginning * of a direct path load, it cannot be maintained by the loader.
ACTIONEither rebuild index partition, re-create the index, or use either * SKIP_UNUSABLE_INDEXES or SKIP_INDEX_MAINTENANCE (Sql*Loader only).