This can occur with with to many rdp connection attempts, someone may be trying to break into your computer/server.
Check your resource monitor network usage, if you see many connections (10, 20+) with svchost.exe (termsvcs) then someone is attempting to break into the system.
Its best practice to limit RDP connections to specific IP addresses or via a VPN to prevent this. However, in some cases this may not be possible, so you may change the port number which may help mitigate the attack.
WARNING, Incorrectly editing your registry can cause your system to become non functional. Proceed at your own risk.
open regedit, and go to "HKEY_LOCAL_MACHINE\System\CurrentControlSet\Control\TerminalServer\WinStations\RDP-Tcp" then select the PortNumber REG_DWORD entry and change the value data in Decimal to the new port number. Restart the service or system to make the change active.,
It can also be cause when a windows servers is running on vmware or hyper-v and in some cases with a stand alone server where hardware has changed. In most cases this error starts after virtual machine resource changes, or some windows updates.
On the computer you are connecting to...
Then go to Computer Configuration > Administrative Templates > Windows Components > Remote Desktop Services > Remote Desktop Session Host > Security
Then choose Require use of specific security layer for remote (RDP) connections
Enable > then choose Security Layer: RDP
Reboot the system.
note: I am not actually sure of the actual cause of this error, if someone has some details please share them below.