ERROR_DS_NAME_NOT_UNIQUE - 8571 (0x217B)
The requested name already exists as a unique identifier.
Updated: Feb 21, 2026
Technical Meaning
The error code ERROR_DS_NAME_NOT_UNIQUE (8571, 0x217B) indicates that a unique identifier requested by the system already exists within the directory service or database. This can occur in various contexts where names are used as identifiers to ensure uniqueness.
Error Details
This error typically arises when an attempt is made to add or modify an object (such as a user, group, or organizational unit) with a name that conflicts with an existing unique identifier within the directory service. The system cannot proceed because it requires all names to be unique to maintain consistency and avoid ambiguity.
Usage Context
This error can occur in scenarios involving Active Directory or other directory services where names are used as primary keys for objects. It is not limited to a specific subsystem but rather pertains to the general operation of maintaining name uniqueness within the directory structure.
Developer Interpretation
When encountering this error, developers should ensure that the names being used for identifiers are unique and do not conflict with existing entries in the directory service. This can be achieved by implementing robust validation logic or using naming conventions that guarantee uniqueness.
Related Errors
ERROR_DS_OBJECT_ALREADY_EXISTS(8572, 0x217C): Indicates an attempt to add an object that already exists.ERROR_DS_NAME_EXCEEDS_MAX_LENGTH(4936, 0x1360): Occurs when a name exceeds the maximum allowed length.
FAQ
Q: Can this error occur in file systems?
A: No, this specific error is related to directory services and not directly to file systems. However, similar errors may exist for file systems that enforce unique names within directories or paths.
Q: Is this a critical error?
A: While it can halt operations requiring name uniqueness, it generally does not pose a severe threat to system stability unless part of a larger issue with the directory service.
Summary
The ERROR_DS_NAME_NOT_UNIQUE (8571) is a specific error indicating that a requested unique identifier already exists within the directory service. Developers should ensure robust name validation and uniqueness checks to avoid this error in their applications.