The remote computer requires Network Level Authentication, which your computer does not support. For assistance, contact your system administrator or technical support.
Or this can also happen:
The remote computer that you are trying to connect to requires Network Level Authentication but your Windows domain controller cannot be contacted to perform NLA. If you are an administrator on the remote computer, you can disable NLA by using the options on the Remote tab of the System Properties dialog box.
1] Change Remote Desktop setting
Going via the Remote Desktop Settings route is the simpler solution. It will work for you and you might not feel the need to enable NLA back on. So, if you are ready for this solution, here is how you go about it. Follow the steps carefully.
1] Go to ‘Run’ and type ‘sysdm.cpl’ and hit the ‘Enter’ button.
2] You are now in the System Properties window. You need to go to the Remote tab.
3] Find the “Allow connections only from computers running Remote Desktop with Network Level Authentication (recommended)” and uncheck this option.
4] Click ‘Apply’ and then click ‘OK’ or hit the ‘Enter’ button to disable Network Level Authentication.
This fix should work because you just undid the only thing that was causing the problem. But just in case it did not work, or you do not want to pursue this route, there is another option which is also simple to follow.
2] Edit Registry (method is more elaborate and needs more attention)
Note: Please backup your data before making changes to the registry of the system.
Follow the steps very carefully and you will be good to go. You have already created your System Restore point so there’s nothing to worry about anymore. So here we go.
1] Go to ‘Run’ and type ‘regedit’ and click ‘OK’ or hit ‘Enter’. This opens the Registry Editor.
2] Look at the left panel in the Registry Editor window and find the registry key called:
3] Select Lsa and then locate Security Packages in the right panel. Double-click on it.
4] Find the Edit Multi-String option and type ‘tspkg’ in the Value data box. This will be the only value.
5] Thereafter, locate the following registry key in the navigation pane: HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Control\SecurityProviders
6] Double-click SecurityProviders in the right-pane to open its properties.
7] Type credssp.dll in the Value data box and let it be the only value.
8] Click ‘OK’ and close the Registry Editor.