Hi, I have been developing a website for some time without using Umbraco ModelsBuilder. I have created a couple of my own models in the /Models folder: ContactModel for the custom contact form and ShowcaseProductModel for my product card. Everything went while I was developing the website in one language. Yesterday, I decided to freeze the development of the features and add two other languages using Vorto.

So, I have studied the ModelsBuilder Wiki and have read and watched some youtube videos of Jeroen Breuer on Vorto. I liked his idea to use the Umbraco.ModelsBuilder.Api to generate models inside my /Models folder instead of inside /App_Data and/or /bin. So, I configured ModelsBuilder in the Web.config

<add key="Umbraco.ModelsBuilder.Enable" value="true" />
<add key="Umbraco.ModelsBuilder.EnableApi" value="true" />
<add key="Umbraco.ModelsBuilder.ModelsMode" value="Nothing" />

I added a dummy Paraplu.cs class inside /Models, installed the ModelsBuilder Custom Tool and configured the Properties of theParaplu.cs` to use it:

I have also added .user file with the same name as the solution ed4u.UmbracoModelsBuilder.user:

<?xml version="1.0" encoding="utf-8"?><configuration>
  <umbraco>
    <modelsBuilder version="3.0.4.0" umbracoUrl="http://localhost:19617" umbracoUser="user" umbracoPassword="password" />
  </umbraco>
</configuration>

Immediately, I got a compilation error as my IIS Express of the Visual Studio 2015 was not running yet and there was nothing listening on port 19617. So I hit Ctrl-F5. It opened my website and I could browse it as well as my Umbraco backend.

Back to models generation. Right clicked the Paraplu.cs file and then Run Custom Tool. I could see the model classes being generated. I have refreshed the cache in the browser and everything seemed still to be working. But I know that one can only be for 100% sure if the Visual Studio is completely restarted. So I did.

When I opened the solution again and hit Ctrl-F5 again, it threw this error at me even before I saw the website:

The error was thrown from ModelsBuilderApplication at line 32 (the long line on the error stack trace below ModelsBuilderApplication at line 55:

if (config.EnableFactory)
    InstallDefaultModelsFactory();

I have tried a lot of things as a workaround but each time it came back to this one error message.

I wonder if it has anything to do with the fact that I have already had 2 (not generated) models before triggering the ModelsBuilder.