ORA-12812
only one PARALLEL or NOPARALLEL clause may be specified
Cause
PARALLEL was specified more than once, NOPARALLEL was specified more than once, or both PARALLEL and NOPARALLEL were specified in a CREATE TABLE, CLUSTER, or INDEX or in an ALTER TABLE or CLUSTER statement, or in a RECOVER command.
Action
Remove all but one of the PARALLEL or NOPARALLEL clauses and reissue the statement.