The remote computer that you are trying to connect to requires Network Level Authentication (NLA), but your Windows domain controller cannot be contacted to perform NLA.

Solution:

1. Open registry editor

In the search box or Run window, type the following, followed by Enter:   regedit

2. Navigate or browse to the following key:

HKEY_LOCAL_MACHINE\SYSTEM\ControlSet001\Control\Terminal Server

3. Locate the fDenyTSConnections subkey, and change the DWORD value to 0.

To enforce the use of RDP 6.0 and NLA, navigate to the following key:

HKEY_LOCAL_MACHINE\SYSTEM\ControlSet001\Control\Terminal Server\WinStations\RDP-Tcp

5. Locate the UserAuthentication subkey, and change the DWORD value to 1.

6.Exit registry editor and restart the computer to make the changes effective.

Note: Please backup the registry key before modifying the above keys.