OpenFileDialog.ShowDialog（）引发异常？

System.ArgumentException

Public ReadOnly Property OpenParser As ICommand
    Get
        Return New RelayCommand(Sub(param As Object) OpenParserExecute(DirectCast(param, Frame)))
    End Get
End Property

Public Sub OpenParserExecute(ByVal mFrame As Frame)
    SaveParserExecute()
    Dim mOpenDialog As OpenFileDialog = OpenDialog
    If mOpenDialog.ShowDialog() Then \' Lines the throws the exception
        CurrentParser = New ParserEditorModel(mOpenDialog.FileName)
        mFrame.Navigate(New ParserEditor(CurrentParser))
    End If
End Sub

at MS.Internal.Interop.HRESULT.ThrowIfFailed(String message)
at MS.Internal.AppModel.ShellUtil.GetShellItemForPath(String path)
at Microsoft.Win32.FileDialog.PrepareVistaDialog(IFileDialog dialog)
at Microsoft.Win32.FileDialog.RunVistaDialog(IntPtr hwndOwner)
at Microsoft.Win32.FileDialog.RunDialog(IntPtr hwndOwner)
at Microsoft.Win32.CommonDialog.ShowDialog()
at WinTransform.GUI.MainWindowModel.OpenParserExecute(Frame mFrame) in C:\\Users\\Alex\\Desktop\\MEDLI\\branches\\WinTransform\\GUI\\ViewModels\\MainWindowModel.vb:line 38