If LoadLibrary() fails (returning NULL), you call GetLastError() to obtain the error number, and FormatMessage() to obtain the error message.
Is LoadLIbrary() failing? If yes, get the error code and error message. Same for FreeLibrary().
If function calls inside this library you are using are failing, refer to their documentation to know how to proceed. They don't seem to be part of Windows.
64-bit versions of Windows only load device drivers that are signed by a code signing certificate issued by a public CA such as Verisign, Thawte, etc. WinIo64.sys must not be deployed on production machines unless a code signing certificate is obtained and used to sign this file. The bundled copy of WinIo64.sys is signed with a self-signed certificate and can only be used on development/test machines with Windows running in a special "test" mode. In order to use the bundled version of WinIo64.sys, you need to take the following steps:
Open an elevated command window by right-clicking the icon and clicking "Run as Administrator".
Type the following command to enable test-signing: