Later versions of Windows may not be able to RDP into older versions that have not had recent updates applied.
This appears to be related to the May 2018 update for windows: https://blogs.technet.microsoft.com/yongrhee/2018/05/09/after-may-2018-security-update-rdp-an-authentication-error-occurred-this-could-be-due-to-credssp-encryption-oracle-remediation/
You can get around this by updating your machines Group Policy.
1. If you go to **Start
** and search **Group Policy
2. Under Group policy, Expand **Computer Configuration
** -> **Administrative Templates
** -> **System
** -> **Credentials Delegation
3. Right Click and **Edit
** the "Encryption Oracle Remediation
4. Set this to **Enabled
** and set **Protection Level: Vulnerable
5. Apply the changes.
Once all updates are applied you should be able to connect to the server.
Once the server has had all the latest updates applied, you can go back into your group policy and revert these settings.