Today I encountered another error whilst doing an upgrade from Exchange 2010 SP2 to SP3. This was an error on my part as I will explain shortly. The error you can get when updating the UM Role is as follows:
“There are no more endpoints available from the endpoint mapper. (Exception from HRESULT: 0x800706D9)”. There are no more endpoints available from the endpoint mapper.”
Simple fix, the windows firewall service is disabled and needs to be enabled, once enabled you need to reboot the Exchange Server, once that is done make sure that the service is started and then run your setup again.
I disabled the service quite a while back that is why I go this error.
Hope it helps.