Now, I did not set out to crash it intentionally, but at least it is fully reproducible. What did I do? Well, I wanted to build a site based on the code I wrote in the blog entry Writing a Subversion-backed VirtualPathProvider for ASP.NET 2.0. So I created a new directory for the site, and simply put the code from the download into a subdirectory (which already exists in the zip file):

Of course I went ahead and opened MyNewWebSite in Visual Studio 2005:

Nothing unexpected so far, I can expand all directories just fine in Solution Explorer:

However, as soon as I hover over SubversionVirtualPathProvider.cs, Solution Explorer goes grey. Totally grey. As in no icons, no tree, no nothing. So I File / Exit Visual Studio 2005 (saying No to saving the solution), and kabooom, here is my friend the error reporting tool:

Oh, and btw, an empty App_Code directory won't do the trick.