What does HRESULT 0xC00E003B (MQ_ERROR_ILLEGAL_PROPERTY_SIZE) mean?

MQ_ERROR_ILLEGAL_PROPERTY_SIZE

Why the exact HRESULT matters

The important part of MQ_ERROR_ILLEGAL_PROPERTY_SIZE 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 fixed-width message identifier supplied with wrong size. Message IDs and correlation IDs have protocol-defined lengths and are not arbitrary byte strings.

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

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

Subsystem context

When diagnosing MQ_ERROR_ILLEGAL_PROPERTY_SIZE, 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_PROPERTY_SIZE, the code-specific boundary is fixed-width message identifier supplied with wrong size.

Minimum useful telemetry

• The first failing property rather than only the aggregate hresult; associate it explicitly with MQ_ERROR_ILLEGAL_PROPERTY_SIZE.
• When diagnosing MQ_ERROR_ILLEGAL_PROPERTY_SIZE, the complete apropid/apropvar/astatus triples in original order; capture the value before cleanup or retry changes it.
• In the MQ_ERROR_ILLEGAL_PROPERTY_SIZE 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_PROPERTY_SIZE 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_PROPERTY_SIZE, 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.

Step-by-step diagnosis

1. Record the unsigned HRESULT, MQ_ERROR_ILLEGAL_PROPERTY_SIZE, and the native API or COM method before a framework replaces it with a generic exception.
2. When diagnosing MQ_ERROR_ILLEGAL_PROPERTY_SIZE, capture the first failing property rather than only the aggregate HRESULT.
3. In the MQ_ERROR_ILLEGAL_PROPERTY_SIZE path, capture the complete aPropID/aPropVar/aStatus triples in original order.
4. Reproduce with the smallest queue/message/property set that still returns MQ_ERROR_ILLEGAL_PROPERTY_SIZE; change one precondition at a time.
5. For MQ_ERROR_ILLEGAL_PROPERTY_SIZE, verify the postcondition after the failed call: queue existence, message presence, directory object state, transaction outcome, or generated output may differ by result.
6. When diagnosing MQ_ERROR_ILLEGAL_PROPERTY_SIZE, apply the code-specific recovery rule: Allocate exactly the documented size and preserve binary data without text conversion.

Retry and cleanup

Allocate exactly the documented size and preserve binary data without text conversion.

When diagnosing MQ_ERROR_ILLEGAL_PROPERTY_SIZE, an immediate loop around the same call is not recovery. In the MQ_ERROR_ILLEGAL_PROPERTY_SIZE path, define who owns cancellation, handle recreation, transaction reconciliation, and duplicate suppression before another attempt is issued.

Avoiding a false diagnosis

In the MQ_ERROR_ILLEGAL_PROPERTY_SIZE 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_PROPERTY_SIZE remains fixed-width message identifier supplied with wrong size.

• In the MQ_ERROR_ILLEGAL_PROPERTY_SIZE path, A successful test under an interactive administrator account does not prove that the production service account has the same profile, token, directory access, or key permissions.
• For this MQ_ERROR_ILLEGAL_PROPERTY_SIZE result, restarting MSMQ before collecting evidence can invalidate handles and erase the first useful event; it is a containment action, not a root-cause diagnosis.

Example

A wrapper building mqpropvariant arrays encounters MQ_ERROR_ILLEGAL_PROPERTY_SIZE. For MQ_ERROR_ILLEGAL_PROPERTY_SIZE, 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_PROPERTY_SIZE, 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_PROPERTY_SIZE, and test that a retry does not duplicate messages or directory objects.

References

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

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