I bought a new external 4TB drive and after a few hit and misses with getting it to mount I managed to get back ups running through time machine for the last month, but now it is not showing on the desktop and failing to mount again. I have tried through disc utility and WD utilities but nothing seems to get it to mount. Any ideas please.
Is it still showing in Disk Utility though greyed out?
Thank you for getting back to me. I managed to get it to mount and run a back up over the weekend so fingers crossed it is now ok. Thank you for looking into this.
Please do share how you made it mount? Will be useful for many others who come across similar problem.