WD Thunderbolt 8TB - Drive in slot b is missing

Hi all,

Every time I connect my external WD Thunderbolt drive (8TB RAID 1 mirrored) to my MacBook Pro (early 2013) I get a warning pop up saying the drive in slot b is missing.

I cannot be 100% but it feels to me that this has been happening since upgrading to Mac OS Sierra.

The drive is functioning fine with all the data there and accessible. If I open WD Drive Utilities and run the diagnosis tests everything passes successfully.

If the drive is on its way out how do I know when the tools say its fine?
If the drive is fine how do I get rid of the annoying (and thus incorrect) message?

Thanks,
Drammy

Did try updating WD Drive Utilities for Mac after your system was updated? The application itself may be improperly reporting a missing drive as a result of needing to be updated.

Yeah, WD Drive Utilities is up-to-date

Should have said - that is the first thing I tried.

The tool says everything is fine.

The pop-up stating the problem appears without the tools running. What’s showing this dialog? Is that a WD Drive Utilities thing?

I have the same problem. It makes me feel impending doom every time I plug in the drive, but then it is working fine.