Twilio Rest API throws Error: Could not load type 'Twilio.TwilioClient' from assembly 'Twilio, Version=1.0.0.0, Culture=neutral, PublicKeyToken=null'

Question

This is the code I'm running in a C# ASP.Net Mvc project. The error thrown identifies that it was thrown at the closed curly bracket ( } ).

    public ActionResult SendSms()
    {
        const string accountSid = "ACCOUNT_SID";
        const string authToken = "AUTH_TOKEN"; 
        TwilioClient.Init(accountSid, authToken);

        var to = new PhoneNumber("+NUMBER");
        var from = new PhoneNumber("+NUMBER");

        var message = MessageResource.Create(
            to: to,
            from: from,
            body: "This is a test.");

        return Content(message.Sid);
    }

I have also tried using

TwilioRestClient restClient = new TwilioRestClient(accountSid, authToken);

In place of the TwilioClient.Init(...); command. The same error produces. Here's the error and stack trace:

[TypeLoadException: Could not load type 'Twilio.TwilioClient' from assembly 
'Twilio, Version=1.0.0.0, Culture=neutral, PublicKeyToken=null'.]
   Twilio.Controllers.SMSController.SendSms() in 
c:\users\crush\Source\Repos\Twilio\Twilio\Controllers\SMSController.cs:34
   lambda_method(Closure , ControllerBase , Object[] ) +61
   System.Web.Mvc.ActionMethodDispatcher.Execute(ControllerBase controller, 
Object[] parameters) +14
   System.Web.Mvc.ReflectedActionDescriptor.Execute(ControllerContext     controllerContext, IDictionary`2 parameters) +157
   System.Web.Mvc.ControllerActionInvoker.InvokeActionMethod(ControllerContext controllerContext, ActionDescriptor actionDescriptor, IDictionary`2 parameters) +27
   System.Web.Mvc.Async.<>c.    <BeginInvokeSynchronousActionMethod>b__9_0(IAsyncResult asyncResult,     ActionInvocation innerInvokeState) +22
   System.Web.Mvc.Async.WrappedAsyncResult`2.CallEndDelegate(IAsyncResult asyncResult) +29
   System.Web.Mvc.Async.WrappedAsyncResultBase`1.End() +49
   System.Web.Mvc.Async.AsyncControllerActionInvoker.EndInvokeActionMethod(IAsyncResult asyncResult) +32
   System.Web.Mvc.Async.AsyncInvocationWithFilters.    <InvokeActionMethodFilterAsynchronouslyRecursive>b__11_0() +50
   System.Web.Mvc.Async.<>c__DisplayClass11_1.    <InvokeActionMethodFilterAsynchronouslyRecursive>b__2() +228
   System.Web.Mvc.Async.<>c__DisplayClass7_0.    <BeginInvokeActionMethodWithFilters>b__1(IAsyncResult asyncResult) +10
   System.Web.Mvc.Async.WrappedAsyncResult`1.CallEndDelegate(IAsyncResult     asyncResult) +10
   System.Web.Mvc.Async.WrappedAsyncResultBase`1.End() +49
   System.Web.Mvc.Async.AsyncControllerActionInvoker.EndInvokeActionMethodWithFilters(IAsyncResult asyncResult) +34
   System.Web.Mvc.Async.<>c__DisplayClass3_6.<BeginInvokeAction>b__3() +35
   System.Web.Mvc.Async.<>c__DisplayClass3_1.<BeginInvokeAction>b__5(IAsyncResult asyncResult) +100
   System.Web.Mvc.Async.WrappedAsyncResult`1.CallEndDelegate(IAsyncResult asyncResult) +10
   System.Web.Mvc.Async.WrappedAsyncResultBase`1.End() +49
   System.Web.Mvc.Async.AsyncControllerActionInvoker.EndInvokeAction(IAsyncResult asyncResult) +27
   System.Web.Mvc.<>c.<BeginExecuteCore>b__152_1(IAsyncResult asyncResult, ExecuteCoreState innerState) +11
   System.Web.Mvc.Async.WrappedAsyncVoid`1.CallEndDelegate(IAsyncResult asyncResult) +29
   System.Web.Mvc.Async.WrappedAsyncResultBase`1.End() +49
   System.Web.Mvc.Controller.EndExecuteCore(IAsyncResult asyncResult) +45
   System.Web.Mvc.<>c.<BeginExecute>b__151_2(IAsyncResult asyncResult, Controller controller) +13
   System.Web.Mvc.Async.WrappedAsyncVoid`1.CallEndDelegate(IAsyncResult asyncResult) +22
   System.Web.Mvc.Async.WrappedAsyncResultBase`1.End() +49
   System.Web.Mvc.Controller.EndExecute(IAsyncResult asyncResult) +26
   System.Web.Mvc.Controller.System.Web.Mvc.Async.IAsyncController.EndExecute(IAsyncResult asyncResult) +10
   System.Web.Mvc.<>c.<BeginProcessRequest>b__20_1(IAsyncResult asyncResult, ProcessRequestState innerState) +28
   System.Web.Mvc.Async.WrappedAsyncVoid`1.CallEndDelegate(IAsyncResult asyncResult) +29
   System.Web.Mvc.Async.WrappedAsyncResultBase`1.End() +49
   System.Web.Mvc.MvcHandler.EndProcessRequest(IAsyncResult asyncResult) +28
   System.Web.Mvc.MvcHandler.System.Web.IHttpAsyncHandler.EndProcessRequest(IAsyncResult result) +9
   System.Web.CallHandlerExecutionStep.System.Web.HttpApplication.IExecutionStep.Execute() +9874329
   System.Web.HttpApplication.ExecuteStepImpl(IExecutionStep step) +48
   System.Web.HttpApplication.ExecuteStep(IExecutionStep step, Boolean& completedSynchronously) +159

What am I doing wrong? I'm using Twilio version 5.13.4, VS 2017, and Windows 8. I also don't see how the message is being sent at all, does the TwilioClient just look for a MessageResource object and send it? Perhaps my misunderstanding of this is why it isn't working, but I followed this tutorial https://www.youtube.com/watch?v=ndxQXnoDIj8 (I assume) accurately and the error still produces. Different c# implementations directly from the Twilio site produce the same error.

UPDATE: I noticed that the version number for Twilio was 5.3.0 in the video and backdated to that, but the same error occurs.

Answer 1

One potential cause is if you name your project "Twilio".