Error with WD MyBoook 3tb

What Mac are you trying to use to erase? What macOS version is it running?

If you open Disk Utility on the Mac, does it "see" the WD? Example:

If so, what does Disk Utility show for "Partition Map" and "Device?" If it fails to see the drive, that is also an important troubleshooting clue.

I used a MyBook Mac Edition for a while and found its firmware and disk formatting quite odd for something that is sold "for Mac." I now only use OWC Mercury Elite Pros for our desktop Macs.

Thank you. MBR is master boot record which is a DOS format dating to ~1983:

https://en.wikipedia.org/wiki/Master_boot_record

3TB drives were not available in 1983 so I suspect that may be the source of the "The disk is too large to be supported by the given partition scheme" advisory.

I think I'd give WD a jingle so get their take on that and see if they can suggest how to reformat the drive.

The other option is to physically remove the disk for the drive enclosure. Yes, I know what sounds like destroying the enclosure, be they are built to be opened. Google "open WD mybook enclosure" so see a lot of YouTube links. That's how i learned how to open mine and, although retired for being a b***head, still works.

With the drive out, you can use an external bare-drive adapter or a bare-drive dock to access the disk. That may let Disk Utility get around some firmware oddness in the MyBook enclosure's firmware and allow access.