I'm getting a large page with a repeating error message:

Errors with this extended error code have the following properties: erroneousElementApiName, erroneousElementType, erroneousFields, severity, actionCallName, parameterName

Does anyone know what might be causing this and how to correct it? I've had a colleague try on a developer account and it worked. Another colleague tried on a developer account and got this same error. 

Thanks.

 

 using (var auth = new Enterprise.SoapClient())
            {
                var userId = "XXX";

                var password = "XXX";
                 
                Enterprise.LoginResult result = auth.login(null, new Enterprise.CallOptions(), userId , password);
   
                var client = new SendSMSContactControllerPortTypeClient();

                client.SendSMSContact(new SessionHeader() { sessionId = result.sessionId }, new CallOptions(), null, null,
                   model.PhoneNumber, model.Message); 
            }


My question is for some reason the "SendSMSContact" returns following error, any sugessions or ideas are greatly appreciated.

Exception Details:

Invalid Session ID found in SessionHeader: Illegal Session. Session not found, missing session hash: This error usually occurs after a session expires or a user logs out.