ERROR_DS_NONEXISTENT_MAY_HAVE - 8387 (0x20C3)
Schema update failed: attribute in may-contain does not exist.
Updated: Feb 21, 2026
Technical Meaning
The error code ERROR_DS_NONEXISTENT_MAY_HAVE with the numeric value 8387 and hexadecimal representation 0x20C3 indicates a failure in updating the schema of an Active Directory. Specifically, it signifies that during the update process, an attribute listed in the may-contain list does not exist.
Error Details
This error typically occurs when attempting to modify or add attributes to an existing object class within the directory service schema. The may-contain list defines which attributes can be optionally present on objects of a particular class. If an attempt is made to include an attribute that is not defined in the schema, this error is generated.
Usage Context
This error code is relevant in scenarios where developers or administrators are performing operations such as adding new attributes to existing object classes or modifying the schema of Active Directory services. It can also appear during automated updates or migrations involving directory service schemas.
Developer Interpretation
When encountering this error, it suggests that there is a mismatch between the expected attribute and the actual schema definition. This could be due to several reasons such as incorrect attribute names, missing definitions in the schema, or issues with the update process itself.
Related Errors
ERROR_DS_ATTRIBUTE_TYPE_UNDEFINED(8195): Indicates an undefined attribute type.ERROR_DS_DRA_SCHEMA_CONFLICT(2346): Conflicts during schema replication.
FAQ
Q: What does this error mean?
A: This error indicates that a specified attribute in the may-contain list of an object class does not exist within the current schema definition.
Q: How can I resolve this issue?
A: Ensure that all attributes listed in the may-contain list are correctly defined and present in the schema. Verify the spelling and names of the attributes to match exactly with those defined in the schema.
Summary
The ERROR_DS_NONEXISTENT_MAY_HAVE error code is a specific indication of a failure during Active Directory schema updates due to missing attribute definitions. Developers should ensure that all attributes are correctly specified and present within the schema before performing such operations.