I was trying to run the MVC4 SPA startup kits and they would hang on the splash screen. This was occurring when running from debug mode in Visual Studio 2012. I was finally able to determine the issue was related to a timeout issue when Durandal was loading the require.js scripts.
This issue occurred on my work computer, for both the Durandal Starter kit and the Hot Towel Starter kit, which both rely on require.js. I didn’t try the other kits.
I found that my work machine was setup to use IISExpress as the default server for debugging and my home computer was set to use the Visual Studio built-in server for debugging. I switched my work computer to use the built-in Visual Studio server and had no more issues. I assume this is an issue with relative urls not working properly in IISExpress, but I didn’t keep digging into to it so not sure if that is truly the case.
To switch to use the built-in server, right click your website project in Solution Explorer, click Properties, then on the ‘Web’ tab of the properties page, select ‘Use Visual Studio Development Server’.