One of the certificates installed inside the VPS is likely to be expired, preventing the connection.
It is necessary to delete the expired certificate using the command line.
1. Get a list of certificates from Remote Desktop store with this command:
C:\Windows\system32> certutil -store "Remote Desktop" | findstr "Serial Before After"
It will output something like this, look for the certificate with the NotAfter date which has passed:
certutil -store | findstr "Serial Before After"
Serial Number: 06376c00aa00648a11cfb8d4aa5c35f4
NotBefore: 5/29/1996 4:02 AM
NotAfter: 1/1/2040 5:59 AM
Serial Number: 46fcebbab4d02f0f926098233f93078f
NotBefore: 4/17/1997 6:00 AM
NotAfter: 10/25/2016 5:59 AM
Serial Number: 1e02240d
NotBefore: 12/14/2001 8:03 AM
NotAfter: 12/14/2002 8:03 AM
Serial Number: 198b11d13f9a8ffe69a0
NotBefore: 10/1/1997 1:00 PM
NotAfter: 12/31/2002 1:00 PM
2. Delete the expired certificate with this command (replacing the bold serial number with your own of course):
C:\Windows\system32> certutil -delstore "Remote Desktop" 198b11d13f9a8ffe69a0
It will output something like this:
certutil -delstore Remote Desktop 198b11d13f9a8ffe69a0
Deleting Certificate 3
CertUtil: -delstore command completed successfully.
The next time you connect via RDP a new self signed certificate should be created allowing you to login.