Aperture size should be odd between 3 and 7

[graiSoft1982]

Start CameraOpenCv.Exe sample and change apperture size to 4 and the program throw an exception.
Aperture size should be odd between 3 and 7
Filename:C:\projects\opencv-files\opencv\modules\imgproc\src\canny.cpp

" at OpenCvSharp.NativeMethods.<>c.<.cctor>b__1591_0(ErrorCode status, String funcName, String errMsg, String fileName, Int32 line, IntPtr userData)
at OpenCvSharp.NativeMethods.imgproc_Canny1(IntPtr src, IntPtr edges, Double threshold1, Double threshold2, Int32 apertureSize, Int32 l2Gradient)
at OpenCvSharp.Cv2.Canny(InputArray src, OutputArray edges, Double threshold1, Double threshold2, Int32 apertureSize, Boolean L2gradient)
at SDKTemplate.OcvOp.Canny(SoftwareBitmap input, SoftwareBitmap output, Algorithm algorithm) in C:\Users\Username\Downloads\opencvsharp_samples-master\CameraOpenCV\OcvOp.cs:line 145
at SDKTemplate.Scenario1_ExampleOperations.ColorFrameReader_FrameArrivedAsync(MediaFrameReader sender, MediaFrameArrivedEventArgs args) in C:\Users\Username\Downloads\opencvsharp_samples-master\CameraOpenCV\Scenario1_ExampleOperations.xaml.cs:line 217"