RDC for MAC cannot connect to TS server with error message "You were disconnected from the Windows-based computer because of problems during the licensing protocol".

the mac clients are running RDC for mac version 2.1 and they cannot connect to Windows 2008 R2 TS server. They get the error "You were disconnected from the Windows-based computer because of problems during the licensing protocol".

really appreciated if someone have a fix for this.

thanks,

/dan