Can't add entitySubjectIdentifier attribute to local entity

Trying to add attribute etc:attribute:entities:entitySubjectIdentifier to a local entity per documentation in https://spaces.at.internet2.edu/display/Grouper/Grouper+local+entities.

Result is:

 Error: Not allowed to assign to member: AttributeDef[name=etc:attribute:entities:entitySubjectIdentifierDef,uuid=a4feba4da40142f19242879d9d586776], 8b220b8132c54beb95957271eb4eb803, to allow this, make sure the attributeDef has setAssignToMember(true), Problem calling method assignAttributeSubmit on edu.internet2.middleware.grouper.grouperUi.serviceLogic.UiV2SubjectAttributeAssignment

The attribute assignment is being treated as if it's being added to a subject, not an entity.

If I edit the assignment to allow it to be set for members, I can add the attribute. But then I can't add a value to it due to another error:

Error: Cannot invoke "edu.internet2.middleware.grouper.entity.Entity.getName()" because "entity" is null, Exception in save: edu.internet2.middleware.grouper.attr.value.AttributeAssignValue, edu.internet2.middleware.grouper.hibernate.ByObject@e0363ca, Problem in HibernateSession: HibernateSession (10bc9d8f): notNew, notReadonly, READ_WRITE_NEW, activeTransaction, session (74265a05), Exception in saveOrUpdate: edu.internet2.middleware.grouper.attr.value.AttributeAssignValue, ByObjectStatic, query: ', cacheable: null, cacheRegion: null, entityName: null, tx type: null, Problem in HibernateSession: HibernateSession (5b7b04bb): new, notReadonly, READ_WRITE_NEW, notActiveTransaction, session (74265a05), Problem calling method attributeAssignAddValueSubmit on edu.internet2.middleware.grouper.grouperUi.serviceLogic.UiV2SubjectAttributeAssignment