POST https://graph.microsoft.com/beta/copilot/admin/catalog/packages/{id}/reassign UnknownError

Question

Hi,
When I try to execute the following endpoint (example):
POST https://graph.microsoft.com/beta/copilot/admin/catalog/packages/T_1acade99-f958-cc25-7f8e-0fc02e5bc446/reassign with the following body:

{
  "userId": "607d9b28-f465-43f2-b35e-0c1c14442393"
}

I receive an error:

{
    "error": {
        "code": "UnknownError",
        "message": "{\"StatusCode\":424,\"Message\":\"An error occurred while reassigning the agent. Please try again later.\"}",
        "innerError": {
            "date": "2026-06-03T14:06:46",
            "request-id": "ea6fd26d-7d86-4b19-b8b2-d4abd175d6f9",
            "client-request-id": "2963832a-dd07-5bdf-b912-37e37f54e60e"
        }
    }
}

Answer 1

The copilotPackage: reassign action is a Microsoft Graph /beta API that reassigns ownership of a Copilot package to another user. From the context, only the following behaviors are documented:

• Endpoint: POST https://graph.microsoft.com/beta/copilot/admin/catalog/packages/{id}/reassign
• Required body:

    {
      "userId": "<new-owner-user-id>"
    }
  

• Required headers:
  • Authorization: Bearer {token}
  • Content-Type: application/json
• Required permissions (least privileged):
  • Delegated: CopilotPackages.ReadWrite.All
  • Application: CopilotPackages.ReadWrite.All
• Successful response: 204 No Content with no response body.

The context does not provide specific causes or remediation steps for the UnknownError / StatusCode 424 that appears when calling this endpoint. It only states that the API is in preview (/beta) and not supported for production, and that access requires a Microsoft Agent 365 license.

Given the available information, the only supported guidance is:

1. Ensure the request matches the documented contract:
   • Use the /beta/copilot/admin/catalog/packages/{id}/reassign URL.
   • Include userId in the JSON body.
   • Include the required headers.
2. Ensure the calling identity has CopilotPackages.ReadWrite.All and that the tenant has the required Microsoft Agent 365 license.
3. Because this is a /beta API and the error is not documented, collect the request-id and date from the error and open a support case so the backend team can investigate the 424 failure for this specific request.

---

References:

• copilotPackage: reassign
• Agent and app Package Management API overview (preview)