400 Error: Data mismatch between Assistant Agent and unknown ent_msg reference

[pmolitor-auditneo]

I encountered the following error when working with an assistant agent:

400: Data mismatch detected for agent asst_...  
The associated enterprise agent ent_msg_... (asst_...) has inconsistent data.  
Apim-request-id: c...

Problem

• I have never heard of or found documentation for ent_msg identifiers.
• It worked fine before, then suddenly started failing with this error.
• I cannot find any references in the docs to explain what ent_msg_* objects are or why a mismatch would occur.
• Creating completely new Agents works, but updating existing ones consistently fails. Having to recreate agents with new identifiers each time is not practical.

Questions

1. What exactly are ent_msg_* objects? Are they part of Enterprise Agents or some internal resource mapping?
2. Under what conditions can this mismatch occur?
3. Is there a known migration, versioning, or data consistency issue that could trigger this?
4. How should I recover or resolve this mismatch without having to create a new agent each time?

Any pointers, docs, or explanations would be helpful.

Thanks.

[chris-clark-serverless]

I have the same issue. When I run the Update call.

               client.Administration.UpdateAgent(assistantId: agent.Id,
                   model: instance.GetModelName(),
                   instructions: instance.GetInstructions(),
                   tools: instance.GetTools(),
                   temperature: 0.1f);

Data mismatch detected for agent asst_XXXX. The associated enterprise agent ent_msg_YYYYYY (asst_XXXX) has inconsistent data