If you are using a Mac you can grab the Remote Desktop connection. Know how to use RDP on MAC.

If you are using a Mac you can grab the Remote Desktop connection client here: https://itunes.apple.com/au/app/microsoft-remote-desktop-10/id1295203466?mt=12

If you are trying to connect to a Windows 2012 R2 server through remote desktop from a Mac, you need to ensure you are using the latest version of Microsoft Remote Desktop Client. This should allow you to connect and bypass any certificate error caused by the self-signed remote desktop certificates used by Windows.

If however, you cannot do this, you can still connect via your older version of Remote Desktop Client for Mac by requesting support to make a group policy change, or making it yourself through the web based console, see: https://www.vpsblocks.com.au/support/Knowledgebase/Article/View/28/0/how-can-i-get-console-access-to-my-vps

The group policy change needs to be:

Computer Configuration\Administrative Templates\Windows Components\Remote Desktop Services\Remote Desktop Session Host\Security

The key is called: Require use of specific security layer for remote (RDP) connections

It needs to be enabled and the security method set to RDP.

Once this is done, restart the "Remote Desktop Services" service and you will be able to connect.