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ERROR_DS_MAPI_ID_NOT_AVAILABLE
Schema update failed: There are no MAPI identifiers available.
ERROR_DS_MAPI_ID_NOT_AVAILABLE is Windows status 8632 (0x000021B8) associated with allocation of a new MAPI identifier during an Active Directory schema update.
Likely impact: Schema updates cannot complete, and forcing identifier reuse risks collisions across applications.
Typical causes
- the identifier pool is exhausted.
- schema extensions consumed IDs without governance.
- duplicate or abandoned schema proposals wasted allocations.
- the update assumes an ID can be recycled.
Troubleshooting steps
- Verify that an unused identifier remains in the supported MAPI ID space.
- Collect schema attribute and proposed identity and current mAPIID assignments.
Useful evidence
- Collect vendor extension inventory.
- Collect forest schema version.
Recovery and retry
Stop allocating ad hoc identifiers, reconcile schema extensions with the schema owner, and use a supported assigned identifier or redesign the extension.
Related errors
ERROR_DS_OID_MAPPED_GROUP_CANT_HAVE_MEMBERS concerns OID-mapped groups; this code concerns exhaustion of MAPI schema identifiers
Example
A product installer requests another MAPI ID in a forest with extensive custom schema. Inventory shows the allocation space is exhausted, requiring schema redesign rather than installer retry.
References
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