System.Collections.ListDictionaryInternal
System.ArgumentException: Cannot marshal: Encountered unmappable character.
   at System.Runtime.InteropServices.Marshal.StringToAnsiString(String s, Byte* buffer, Int32 bufferLength, Boolean bestFit, Boolean throwOnUnmappableChar)
   at System.StubHelpers.CSTRMarshaler.ConvertToNative(Int32 flags, String strManaged, IntPtr pNativeBuffer)
   at OpenCvSharp.NativeMethods.imgcodecs_imread_Windows(String fileName, Int32 flags, IntPtr& returnValue)
   at OpenCvSharp.NativeMethods.imgcodecs_imread(String fileName, Int32 flags, IntPtr& returnValue)
   at OpenCvSharp.Mat..ctor(String fileName, ImreadModes flags)
   at ParticleConverter.util.ImageConverter.Load(String imagePath)
   at ParticleConverter.MainWindow.ImageFileLoad()