Switch desktop right and left by Ctrl+n and Ctrl+h does not work

[hajime-f]

SylphyHorn is a great work to enhance the virtual desktop environment.

I would like to use shortcuts of Ctrl+n and Ctrl+h to switch the desktop to right and left, respectively, but it does not work well.
The App Log indicates some exceptions written below:

System.ArgumentException: パス名を空にすることはできません。
   場所 System.IO.FileStream.Init(String path, FileMode mode, FileAccess access, Int32 rights, Boolean useRights, FileShare share, Int32 bufferSize, FileOptions options, SECURITY_ATTRIBUTES secAttrs, String msgPath, Boolean bFromProxy, Boolean useLongPath, Boolean checkHost)
   場所 System.IO.FileStream..ctor(String path, FileMode mode, FileAccess access, FileShare share, Int32 bufferSize, FileOptions options, String msgPath, Boolean bFromProxy)
   場所 System.IO.FileStream..ctor(String path, FileMode mode)
   場所 SylphyHorn.UI.Controls.UnlockImageConverter.Convert(Object value, Type targetType, Object parameter, CultureInfo culture)

I appreciate it if you kindly improve the function.