Microsoft Blend 2013 "无法找到Windows运行时类型'Windows. app

当我在Blend for Visual Studio 2013中打开任何Windows 8.1项目(包括在应用程序本身中创建的空白新项目)时，我得到以下XAML文件的设计器问题:

An unhandled exception has occured
Click here to reload the designer
Details:
System.TypeLoadException
Could not find Windows Runtime type 'Windows.ApplicationModel.Package'.
at Microsoft.Expression.HostUtility.Platform.AppContainerProcessDomainFactory.CreateDesignerProcess(String applicationPath, String clientPort, Uri hostUri, IDictionary environmentVariables, Int32& processId, Object& processData)
at Microsoft.Expression.DesignHost.Isolation.Primitives.ProcessDomainFactory.ProcessIsolationDomain..ctor(ProcessDomainFactory factory, IIsolationBoundary boundary, AppDomainSetup appDomainInfo, FrameworkName targetFramework, String identifier, String baseDirectory)
at Microsoft.Expression.DesignHost.Isolation.Primitives.ProcessDomainFactory.CreateIsolationDomain(IIsolationBoundary boundary)
at Microsoft.Expression.HostUtility.Platform.AppContainerProcessDomainFactory.CreateIsolationDomain(IIsolationBoundary boundary)
at Microsoft.Expression.DesignHost.Isolation.Primitives.IsolationBoundary.Initialize()
at Microsoft.Expression.DesignHost.Isolation.Primitives.IsolationBoundary.CreateInstance[T](Type type)
at Microsoft.Expression.DesignHost.Isolation.IsolatedObjectFactory.Initialize()
at Microsoft.Expression.DesignHost.Isolation.IsolationService.AttachEvents(IsolatedObjectFactory objectFactory)
at Microsoft.Expression.DesignHost.Isolation.IsolationService.CreateLease(IIsolationTarget isolationTarget)
at Microsoft.Expression.DesignHost.IsolatedDesignerService.CreateLease(IIsolationTarget isolationTarget, CancellationToken cancelToken, DesignerServiceEntry& entry)
at Microsoft.Expression.DesignHost.IsolatedDesignerService.IsolatedDesignerView.CreateDesignerViewInfo(CancellationToken cancelToken)
at Microsoft.Expression.DesignHost.Isolation.IsolatedTaskScheduler.InvokeWithCulture[T](CultureInfo culture, Func`2 func, CancellationToken cancelToken)
at Microsoft.Expression.DesignHost.Isolation.IsolatedTaskScheduler.<>c__DisplayClassa`1.<StartTask>b__6()
at System.Threading.Tasks.Task`1.InnerInvoke()
at System.Threading.Tasks.Task.Execute()"

windows 8.1项目用来加载没有问题，我没有使用设计器几个星期，现在我得到这个错误。我用的是Windows 10。WPF项目加载正常。

有没有人有类似的问题或有一个想法如何解决它?提前感谢您的帮助。