I’m having the same problem, and WD Support has been no help. All the fixes they suggested–including power down, connect directly to computer via ethernet, reset–I did over and over with no results.
The only clue one person gave me on a post here is that the Yellow Light issue may mean that the drive can’t boot up."
If this is the case, then the question is–is the problem in the Boot Partition, and, if so, can it be fixed? Or is there some other way to boot the drive?