Hi kelvyim, are you still having problems?
I have a 12 TB My Book Duo (USB, not Thunderbolt) connected with a USB-C cable, and for the almost-a-year I’ve had it, it’s been problematic. I sent it in to WD once to be repaired or replaced and it continues to act up. I periodically get warnings about RAID configuration errors, then a day or two later Drive Genius reports an error, usually something serious. I run tests (always seems to pass), then every 2-3 months need to reformat the drive and start over from a Time Machine backup.
I did find this post that seemed to help, at least for a while. Error in RAID Configuration - #16 by bjcreative
I can’t locate the post now, but read somewhere on this forum that some WD software that’s still installed by WD is incompatible with several of the latest versions of macOS.
I recently re-installed my OS (Mojave) and deleted the offending WD software, and if the errors continue I will replace the with something other than a WD product. Similar issues have been happening to Mac users for over five years now, so I figure WD has had plenty of time to address it.
Best of luck!
