PRCD-02102
failed to create or modify service {0} to have cardinality DUPLEX for pluggable database {1} with cardinality {2}
Cause
An attempt to create or modify the specified service with cardinality DUPLEX was rejected because its pluggable database had cardinality 1 or the database was configured on one server.
Action
Create or modify the service to have cardinality SINGLETON or UNIFORM for the pluggable database with cardinality 1 or add more instances to the database and increase the pluggable database's cardinality to 2 or ALL.