Symptoms
When Unified Messaging (UM) is enabled, you can't edit the calling rules and you receive the following error message:
"The server EXHR-01599.EXCHRSV.contoso.com returned an invalid response message. Error 0xe0434352 (Unknown error (0xe0434352)) from EXHR-01599.EXHR 01599.EXCHRSV.contoso.com(IUMPlayOnPhone.ExecutePoPRequest)."
Resolution
To fix this issue, install the following security update, as appropriate: