Oracle Error ORA-23410: materialized view “string”.”string” is already in a refresh group

Oracle Error Message

ORA-23410: materialized view “string”.”string” is already in a refresh group

Reason for the Error

A materialized view of the same name is already in a refresh group.

Solution

Subtract the materialized view from the current refresh group and add it to its new refresh group, or combine the two refresh groups into a single refresh group.