Connection closed error
Note: Edited to remove the issue I was having, and simply offer an explanation in case anyone else has this issue.
If you consistently get a "Connection closed" error with description "The connection was ended because of a network error. Please try connecting to the remote computer again." when trying to open up applications from the OSX client to a Windows 2003 server, and a Windows client works fine, the issue is likely related to your FIPS policy settings.
In your local policies (administrative tools), make sure FIPS is not set as required. Then in Terminal Services configuration do the same thing; set the security level to "high", not "FIPS".
Apparently, even though the 2X client communicates via SSL, then the remote desktop mechanism (for lack of a better term) that operates between the 2X service and Terminal Services runs on the server itself, there is something proxied from the OSX system such that it still does not support FIPS requirements.
I believe this to be due to Windows 2003 being unable to support the "authentication" or "identity verification" options in Terminal Services.
