I have just downloaded 2X Client RDP for Mac. I am trying to connect to a Windows PC (which is also on my desk, both plugged into the Gigabit switch on my desk). When I attempt to connect, using the PC name or IP address, I get an error dialog from 2X with title “Failed to connect to server”, and message “An authentication error has occurred. The Local Security Authority cannot be contacted.” When I connect to the same PC from the same Mac using Microsoft’s RDP Client for Mac, it gives me a warning about the certificate because the root is not a known, trusted root, but then it connects and works. The Mac is a brand new Macbook Pro Retina 15”, which came with OS X 10.9 Mavericks installed. The Windows PC is running Windows 7 x64 Ultimate. I also tried to connect to another PC running Windows 8.1 and got the same error message. I can also connect to the Windows 8.1 PC just fine using Microsoft’s RDP client for Mac. Help?