What does HRESULT 0xC00E007B (MQ_ERROR_ILLEGAL_MQPRIVATEPROPS) mean?

MQ_ERROR_ILLEGAL_MQPRIVATEPROPS

Operational meaning

The important part of MQ_ERROR_ILLEGAL_MQPRIVATEPROPS is not only whether the call failed, but which MSMQ subsystem had enough information to return this specific result. In this case the decisive subject is private-computer property structure is empty or null. MQGetPrivateComputerInformation requires a coherent MQPRIVATEPROPS request.

For MQ_ERROR_ILLEGAL_MQPRIVATEPROPS, MSMQ uses arrays whose indexes bind a property identifier, an MQPROPVARIANT value, and optionally a status result. When diagnosing MQ_ERROR_ILLEGAL_MQPRIVATEPROPS, misaligned counts or reordered arrays can make the logged property differ from the one actually rejected.

When diagnosing MQ_ERROR_ILLEGAL_MQPRIVATEPROPS, validation occurs in layers: identifier recognition, variant type, buffer shape, value range, required companions, and operation eligibility. In the MQ_ERROR_ILLEGAL_MQPRIVATEPROPS path, these layers correspond to different MSMQ HRESULTs and different fixes.

Where to draw the boundary

When diagnosing MQ_ERROR_ILLEGAL_MQPRIVATEPROPS, do not merge this result with other property failures: identifier, VARTYPE, value, size, required companions, and operation eligibility are diagnosed by different codes. For MQ_ERROR_ILLEGAL_MQPRIVATEPROPS, the code-specific boundary is private-computer property structure is empty or null.

Evidence to preserve

• The first failing property rather than only the aggregate hresult; associate it explicitly with MQ_ERROR_ILLEGAL_MQPRIVATEPROPS.
• When diagnosing MQ_ERROR_ILLEGAL_MQPRIVATEPROPS, the complete apropid/apropvar/astatus triples in original order; capture the value before cleanup or retry changes it.
• In the MQ_ERROR_ILLEGAL_MQPRIVATEPROPS path, the api name and whether the structure was input, output, or both; compare it with a known-good call using the same account and queue type.
• For this MQ_ERROR_ILLEGAL_MQPRIVATEPROPS result, record the queue path or format name, local/remote placement, transactional flag, caller SID, process build, and UTC correlation ID when they apply.

For MQ_ERROR_ILLEGAL_MQPRIVATEPROPS, log certificate thumbprints, provider names, SIDs, GUIDs, lengths, and hashes where useful, but do not log private keys, symmetric keys, credentials, or confidential message bodies.

Diagnostic sequence

1. Record the unsigned HRESULT, MQ_ERROR_ILLEGAL_MQPRIVATEPROPS, and the native API or COM method before a framework replaces it with a generic exception.
2. When diagnosing MQ_ERROR_ILLEGAL_MQPRIVATEPROPS, verify the postcondition after the failed call: queue existence, message presence, directory object state, transaction outcome, or generated output may differ by result.
3. In the MQ_ERROR_ILLEGAL_MQPRIVATEPROPS path, capture the complete aPropID/aPropVar/aStatus triples in original order.
4. For this MQ_ERROR_ILLEGAL_MQPRIVATEPROPS result, capture the API name and whether the structure was input, output, or both.
5. Reproduce with the smallest queue/message/property set that still returns MQ_ERROR_ILLEGAL_MQPRIVATEPROPS; change one precondition at a time.
6. When diagnosing MQ_ERROR_ILLEGAL_MQPRIVATEPROPS, apply the code-specific recovery rule: Initialize cProp and parallel arrays for the exact private-computer properties needed.

Handling and recovery

Initialize cProp and parallel arrays for the exact private-computer properties needed.

When diagnosing MQ_ERROR_ILLEGAL_MQPRIVATEPROPS, do not hide this HRESULT behind an unlimited framework retry. In the MQ_ERROR_ILLEGAL_MQPRIVATEPROPS path, require a verified precondition change and preserve the original correlation identifier across the next attempt.

Nearby failure boundaries

In the MQ_ERROR_ILLEGAL_MQPRIVATEPROPS path, changing a queue ACL or restarting the service does not correct an invalid identifier, VARTYPE, value, structure, or property combination. The specific focus for MQ_ERROR_ILLEGAL_MQPRIVATEPROPS remains private-computer property structure is empty or null.

• In the MQ_ERROR_ILLEGAL_MQPRIVATEPROPS path, restarting MSMQ before collecting evidence can invalidate handles and erase the first useful event; it is a containment action, not a root-cause diagnosis.
• For this MQ_ERROR_ILLEGAL_MQPRIVATEPROPS result, granting broad queue or certificate permissions may mask the symptom while creating a security defect. For MQ_ERROR_ILLEGAL_MQPRIVATEPROPS, test the exact identity and access needed by the operation.

Worked example

A wrapper building mqpropvariant arrays encounters MQ_ERROR_ILLEGAL_MQPRIVATEPROPS. For MQ_ERROR_ILLEGAL_MQPRIVATEPROPS, it logs the rejected property index and rebuilds the request from a typed schema instead of retrying the same arrays. When diagnosing MQ_ERROR_ILLEGAL_MQPRIVATEPROPS, the acceptance test then changes only the decisive precondition and confirms both the HRESULT and the actual queue/message state.

Automated coverage should preserve the original arrays/identities, confirm that cleanup is safe after MQ_ERROR_ILLEGAL_MQPRIVATEPROPS, and test that a retry does not duplicate messages or directory objects.

References

• Microsoft: MSMQ message properties — source used for the MQ_ERROR_ILLEGAL_MQPRIVATEPROPS analysis.
• Microsoft: MQCreateQueue — source used for the MQ_ERROR_ILLEGAL_MQPRIVATEPROPS analysis.
• Microsoft: Message Queuing error and information codes — source used for the MQ_ERROR_ILLEGAL_MQPRIVATEPROPS analysis.
• Microsoft: queue properties and MQQUEUEPROPS — source used for the MQ_ERROR_ILLEGAL_MQPRIVATEPROPS analysis.

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