SAP Message USMD2304 - Entity type &2 cannot be processed with change request &3

Diagnosis You are processing an entity in single processing with change requestV3. now you want to add entities of type v2 to change request v3.This is not possible, because type &V1& of change request &V3& isnot defined for processing of entity type &V2&. System Response Changes to the entity type are ignored.