Issues with my iMac Time Machine detecting my WD MyBook Live

I recently started experiencing issues with my Time Machine software on my iMac not communicating with or even detecting my WD MyBook Live external HD. I’m not sure why. It is still connected directly to my router, nothing has changed in my set-up. Any ideas? Suggestions?

Thanks 

JSFabbri,

What happens if you try to link your WD My Book Live Personal Cloud Storage device with your Apple Mac computer by means of mapping the Time Machine share using the AFP protocol?

Additional instructions are available in the following link:

http://wdc.custhelp.com/app/answers/detail/a_id/2686/

If it does not correct the issue, does a reboot under Settings> Utilities> Device Restart provide any change?