751e44c4__Error_Codes___ServiceNow_Wiki__Description
[Error / Data Code] 64 [Error] LDAP_NAMING_VIOLATION [Description] 
Indicates that the add or modify DN operation violates the schema's structure rules. For example, The request places the entry subordinate to an alias. The request places the entry subordinate to a container that is forbidden by the containment rules. The RDN for the entry uses a forbidden attribute type.
LDAP Error Codes - ServiceNow Wiki
Description