Question

Azure web role (MVC 3 project) wont’ start with Twilio controller class

• I have an MVC 3 app that is hosted on MS Azure. It publishes to Azure Web role – No problems.
• I added the Nuget Twilio and Twilio.Mvc packages. It still published to Azure Web role – No problems.
• I added a class that inherits from the Mvc.TwilioController base class and subsequently the Azure web role no longer starts.
• If I remove the TwilioController class inheritance the web role starts.

The projects publishes, runs and twilio functions fine in my local VS Azure emulator environment.

The project References; Twilio.api, Twilio.mvc, Twilio.Twiml, RestSharp, and NewtonSoft.Json are all set to CopyLocal=True.

All Azure Diagnostic logging/tracing is enabled and sending to table storage every 5 seconds but no log data is available when the web role fails to start. Note: If I comment out the twilioController I get an abundance of log data so Azure Diags are configured correctly.

Because the web role continues to abort/cycle/abort, there is no opportunity to RDP to the vm for further troubleshooting.

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The following two errors are written to the failing web role’s Windows System Event Log about every minute:

The application ‘/’ belonging to site ‘1273337584’ has an invalid AppPoolId ‘ca5c9ecb-e68d-4f3a-84c2-c0b4430373e9’ set. Therefore, the application will be ignored.

.

Site 1273337584 was disabled because the root application defined for the site is invalid. See the previous event log message for information about why the root application is invalid.

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Steps to reproduce (exact steps):

1. Install Azure Sdk v 1.6
2. Create a new project using the Azure template (visual studio 10 sp1)
3. Choose the Asp.net MVC 3 Web Role
4. Build and Publish to Azure
5. Success – Web Role starts
6. Add Nuget Package “Twilio” version 3.3.2
7. Add Nuget Package “Twilio.Mvc” version 3.1.3
8. Build and Publish To Azure
9. Success – Web Role starts
10. Create an empty controller (HelloController). See below code snippet.
11. Add TwilioController base class (e.g. Public Class HelloController : TwilioController)
12. Build and Publish to Azure
13. Fail – the web role just cyles/aborts/cyles.
14. Comment out TwilioController (e.g. Public Class HelloController // :TwilioController)
15. Buld and Publish to Azure

16. Success – web role starts

    using System.Web.Mvc;
    using Twilio.TwiML.Mvc;
      namespace WindowsAzureProject857481.Controllers
        {
            public class HelloController : TwilioController
            {
                //
                // GET: /Hello/
    
                public ActionResult Index()
                {
                    return View();
                }
    

Any ideas appreciated.

Thanks,
Jim

Answer 1

Jim:

I work for Twilio, and own the .NET helper library.

Whats happening is that the Twilio.Mvc assembly is looking for 2.0 version the System.Web.Mvc assembly, since that’s what its built against. Its not finding it because its obviously not being packaged with your MVC 3 project.

The fix if fairly easy. Get the Twilio.Mvc source, change the reference to the newer version of MVC and recompile the assembly. I believe our support team is going to contact you with a version I built for you if you don’t want to do it yourself.

I think there is probably also a way to use assembly binding redirects to fix the problem as well, if you wanted to try that.

Devin