Oracle Solution for Error ora-26027

ORA-26027: unique index string.string partition string initially in unusable state

What triggered the Error:

partition of a unique index is in IU state (a unique index ** cannot have index maintenance skipped via SKIP_UNUSABLE_INDEXES).

What should we do to fix it:

ther rebuild the index or index partition, or use ** SKIP_INDEX_MAINTENANCE if the client is SQL*Loader.