创建Silverlight应用程序时报错？[
刚刚配好Silverlight，想创建第一个Silverlight应用程序！
MainPage.xaml页面的视图加载错误！
如下：
发生了未经处理的异常
详细信息：
System.NullReferenceException
Object reference not set to an instance of an object.
at Microsoft.Windows.Design.Platform.SilverlightMetadataContext.SilverlightXamlExtensionImplementations.<GetXmlNamespaceCompatibilityMappings>d__8.MoveNext()
at MS.Internal.Design.Metadata.ReflectionProjectNode.BuildSubsumption()
at MS.Internal.Design.Metadata.ReflectionProjectNode.SubsumingNamespace(Identifier identifier)
at MS.Internal.Design.Markup.XmlElement.BuildScope(PrefixScope parentScope, IParseContext context)
at MS.Internal.Design.Markup.XmlElement.ConvertToXaml(XamlElement parent, PrefixScope parentScope, IParseContext context, IMarkupSourceProvider provider)
at MS.Internal.Design.DocumentModel.DocumentTrees.Markup.XamlSourceDocument.FullParse(Boolean convertToXamlWithErrors)
at MS.Internal.Design.DocumentModel.DocumentTrees.Markup.XamlSourceDocument.get_RootItem()
at Microsoft.Windows.Design.DocumentModel.Trees.ModifiableDocumentTree.get_ModifiableRootItem()
at Microsoft.Windows.Design.DocumentModel.MarkupDocumentManagerBase.get_LoadState()
at MS.Internal.Host.PersistenceSubsystem.Load()
at MS.Internal.Host.Designer.Load()
at MS.Internal.Designer.VSDesigner.Load()
at MS.Internal.Designer.VSIsolatedDesigner.VSIsolatedView.Load()
at MS.Internal.Designer.VSIsolatedDesigner.VSIsolatedDesignerFactory.Load(IsolatedView view)
at MS.Internal.Host.Isolation.IsolatedDesigner.BootstrapProxy.LoadDesigner(IsolatedDesignerFactory factory, IsolatedView view)
at MS.Internal.Host.Isolation.IsolatedDesigner.BootstrapProxy.LoadDesigner(IsolatedDesignerFactory factory, IsolatedView view)
at MS.Internal.Host.Isolation.IsolatedDesigner.Load()
at MS.Internal.Designer.DesignerPane.LoadDesignerView()
各位大侠，多多支援啊！
[解决办法]
应该是你安装环境有问题，你的代码我拷贝过来试试，运行都没问题！
[解决办法]
你的安装有问题，如果在XP环境下，要先安装XPSP3，然后安装VS2010,然后安装VS2010 SP1，然后安装silverlight控件，然后安装silverlight Tools,然后安装silverlight SDK，关键是VS2010一定要好用，弄几个试试，我当时安装可下了好大一番工夫。
