Downloaded update...mstsc.exe is not available

The error message is wrong and this will be fixed soon. You can switch to embedded mode instead of external mode or download the Microsoft RDP client for Mac.

Strange. I was using Embedded mode before the update. I must have nuked my prefs or something without realizing it :)

Thanks for the quick response on a Sunday evening :)

I don't think see. The external mode was not implemented and this use to be the default on Windows (since mstsc.exe is always installed). While it was not implemented, RDM Mac was always using the embedded mode.