Symptoms
Office 365 Subdomain Form.
In case Microsoft Partner Center API returns generic Bad Request error:
ERROR aps_endpoint: Microsoft.Store.PartnerCenter.Exceptions.PartnerException: Bad Request
Endpoint host does not handle is correctly and throws the same "code":500, "message":"Bad Request" to the Customer CP interface directly (for both CCPv1 and CCPv2).
Cause
Software-related issue #APSA-19588: "Unclear error message in the 'Use an existing Microsoft account' scenario".
Resolution
Contact pta@odin.com or TAM to trace the status of the issue.