If you are connecting to a Windows Server that uses a dedicated licensing role, the service itself may be hung, returning a spurious 0x7.
This is the most common fix for Error 0x3/0x7. The client may be trying to use an old password or a saved session ticket that the gateway no longer accepts.
Capture traffic on the RDP client during connection attempt. Filter for: rdp error code 0x3 extended error code 0x7
If you see an alert like “certificate unknown” (46) or “unsupported certificate” (43), the client rejected the server’s certificate.
If connecting through a gateway:
If direct connection works, the problem is isolated to the gateway certificate.
Combined, 0x3 + 0x7 tells you: The RDP client connected to the server, but the server failed to provide an acceptable certificate during the security handshake, so the session was forcibly closed. If you are connecting to a Windows Server
The RDP client often caches the last used password. If the password changed on the server side but not in the client cache, Error 0x7 occurs.
While the error suggests an "internal" problem, the most common causes are identity and permission-related, rather than hardware or OS corruption. This is the most common fix for Error 0x3/0x7