I have a 3Tb ext HDD connencted via USB to my iMac. It has worked fine for the last year. Today-suddenly- my iMac will not see the drive under spotlight, disk utility or “about this mac”. Nothing. Nowhere. NADA. I do not have any WD apps on my machine. Help!
Make sure you test the drive on a different computer and with a different cable.
Does the light of the drive comes up?
It’s the external drive a Passport or a My Book?