Remote Desktop Connection Error Code 0x904 Extended Error Code 0x7 Full (Ultimate)

Error code 0x904 with extended error 0x7 occurs when a Remote Desktop (RDP) client fails to establish a session because the client cannot retrieve or validate the remote machine’s user or session information. This usually indicates a connection or authentication failure between the RDP client and the Remote Desktop Gateway, broker, or host.

If your network has a Maximum Transmission Unit (MTU) mismatch (e.g., VPN or PPPoE connections), the HTTP CONNECT packets sent to the RD Gateway may be fragmented. The server sees a malformed request and returns an invalid response, triggering 0x904. Error code 0x904 with extended error 0x7 occurs

The RD Gateway server is presenting a certificate that the client does not trust. Specifically: VPN or PPPoE connections)