After I have installed the Visual Studio SP1 and the .net framework 3.5 SP1, I get this error when I open a Visual Studio 2008 Professional in experimental hive: Recipe framework error. Object reference not set to an instance of an object. Before the SP1 installation, the factory was working just fine for more than three months. I have the source installation. I already tried uninstalling the factory and the Visual Studio SP1. Then I installed the .net framework 3.5 and the factory and the problem persists.
 
This is the rest of the error.
System.NullReferenceException: Object reference not set to an instance of an object.
at Microsoft.Practices.RecipeFramework.VisualStudio.Templates.VSTemplatesService.GetRegistryKey(Guid PackageGuid, Boolean registering)
at Microsoft.Practices.RecipeFramework.VisualStudio.Templates.VSTemplatesService.ReadRegistryData()
at Microsoft.Practices.RecipeFramework.VisualStudio.Templates.VSTemplatesService..ctor(RegistryKey currentVsRegistryKey)
at Microsoft.Practices.RecipeFramework.VisualStudio.RecipeManagerPackage.OnCreateService(IServiceContainer container, Type serviceType)
at Microsoft.VisualStudio.Shell.Package.GetService(Type serviceType)
at Microsoft.VisualStudio.Shell.Package.System.IServiceProvider.GetService(Type serviceType)
at Microsoft.Practices.ComponentModel.Site.GetService(Type service)
at Microsoft.Practices.ComponentModel.ServiceHelper.CheckDependencies(Object component, IServiceProvider provider)
at Microsoft.Practices.ComponentModel.ServiceHelper.CheckDependencies(IComponent component)
at Microsoft.Practices.RecipeFramework.VisualStudio.RecipeManagerPackage.OnCreateService(IServiceContainer container, Type serviceType)
at Microsoft.VisualStudio.Shell.Package.GetService(Type serviceType)
at Microsoft.Practices.RecipeFramework.VisualStudio.RecipeManagerPackage.Initialize()