What does Windows error code 1720 (RPC_S_CANT_CREATE_ENDPOINT) mean?

RPC_S_CANT_CREATE_ENDPOINT

Endpoint creation happens before endpoint-map discovery can help

RPC_S_CANT_CREATE_ENDPOINT indicates that the server runtime failed to create a local endpoint for a selected protocol sequence. The concrete resource depends on the transport: an RPC-over-TCP endpoint is a TCP port, while an RPC-over-named-pipes endpoint is a named pipe.

This is not equivalent to a client being unable to find the endpoint. The server failed while establishing the address on which it intended to listen.

What to capture

• Log the protocol sequence and requested endpoint passed to RpcServerUseProtseqEp*.
• For explicit endpoints, check whether another process or server instance already owns the same transport-specific endpoint.
• For dynamic endpoints, inspect RPC extended error information and underlying transport/resource failures rather than guessing a fixed port.
• Confirm the endpoint format is valid for the chosen protocol sequence; a TCP port and a named-pipe endpoint are not interchangeable.

Endpoint mapper registration should be investigated only after the runtime has successfully created server bindings. It cannot publish an endpoint that the server failed to create.

References

• Microsoft: Specifying Endpoints
• Microsoft: Extended RPC error locations
• MS-RPCE endpoint registration