Your computer can’t connect to the Remote Desktop Gateway server.

When receiving the error can’t connect to the Remote Desktop Gateway when trying to connect to RDWeb this can sometimes be fixed by changing the below Registry setting.


HKLM\SYSTEM\CurrentControlSet\Control\Lsa\LmCompatibilityLevel

Set the value to 3 or higher

SettingDescriptionRegistry security level
Send LM & NTLM responsesClient devices use LM and NTLM authentication, and they never use NTLMv2 session security. Domain controllers accept LM, NTLM, and NTLMv2 authentication.0
Send LM & NTLM – use NTLMv2 session security if negotiatedClient devices use LM and NTLM authentication, and they use NTLMv2 session security if the server supports it. Domain controllers accept LM, NTLM, and NTLMv2 authentication.1
Send NTLM response onlyClient devices use NTLMv1 authentication, and they use NTLMv2 session security if the server supports it. Domain controllers accept LM, NTLM, and NTLMv2 authentication.2
Send NTLMv2 response onlyClient devices use NTLMv2 authentication, and they use NTLMv2 session security if the server supports it. Domain controllers accept LM, NTLM, and NTLMv2 authentication.3
Send NTLMv2 response only. Refuse LMClient devices use NTLMv2 authentication, and they use NTLMv2 session security if the server supports it. Domain controllers refuse to accept LM authentication, and they will accept only NTLM and NTLMv2 authentication.4
Send NTLMv2 response only. Refuse LM & NTLMClient devices use NTLMv2 authentication, and they use NTLMv2 session security if the server supports it. Domain controllers refuse to accept LM and NTLM authentication, and they will accept only NTLMv2 authentication.5

For more info see Network security LAN Manager authentication level (Windows 10) – Windows security | Microsoft Docs

If you found this article helpful, would you consider buying me a Coffee?