MarkDownPad打开时出现错误，求各位帮忙看看

HeatOnBeat 2017-03-02 07:32:22

本来MarkDown打开的时候没问题，后来用的时候，一打开就出现未知异常，（对了，我用的是Windows8.1的系统）出现的错误框提示:Unexpected Error
An unexpected error has occurred
The invocation of the constructor on type 'MarkDownPad2.UserControls.MarkdownEditor' that matches the specified binding constraints threw an exception.
然后我打开软件启动的错误日志文件，显示:
2017-02-28 22:14:26.9470|ERROR|MarkdownPad2.UI.MainWindow|Unhandled exception occurred
EXCEPTION:
System.Windows.Markup.XamlParseException The invocation of the constructor on type 'MarkdownPad2.UserControls.MarkdownEditor' that matches the specified binding constraints threw an exception. System.Object Load(System.Xaml.XamlReader, System.Xaml.IXamlObjectWriterFactory, Boolean, System.Object, System.Xaml.XamlObjectWriterSettings, System.Uri)
FileNotFoundException 找不到指定的模块。 (Exception from HRESULT: 0x8007007E) Void ThrowExceptionForHRInternal(Int32, IntPtr)

求各位帮忙给看一下，到底是什么原因啊？

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