The customer reported this issue
from their Windows 10 v1909 laptop, connecting to a outsider vendors (OV) Windows 2016 RD Web Access box.
Before we get onto what the Outside Vendor recommended, here’s the fix I’d suggest:
Server-side fix
Set the EnforceChannelBinding registry value to 0 (zero) to ignore missing channel bindings on the Gateway server. To do this, locate the following registry subkey, and use the given specifications:
HKLM\Software\Microsoft\Windows NT\CurrentVersion\TerminalServerGateway\Config\Core
Type: REG_DWORD
Name: EnforceChannelBinding
Value: 0 (Decimal)
Note By default, the EnforceChannelBinding value does not exist on the Gateway server. You must create this value.– Microsoft: Terminal Services client connection error 0xC000035B when you use LmCompatibility
The Outside Vendor’s IT team advised: