My Book Mac USB3 Freezing my 2013 MacPro

Hi, sorry to hear about your problem. Have you tried some of the basic troubleshooting steps like using another USB cable or connecting the My Book to another PC? Your issue seem to be related to a data corruption problem, note that this can happen for several reasons such as power outages, accidental physical damage, internal component failure, and computer viruses, just to name a few. 

You can also try to contact tech support directly for direct help on this. 

http://support.wdc.com/country/index.asp?lang=en