After years ou use my WD Drive is no more recognized by my MacBook Pro

Using Time Machine for my back-up for years without any problem, yesterday, suddenly Time Machine sent me a message telling that the day before it could not terminate the saving and could not now find the WD Disk. I tried the disk utility which searched the disks and could not find any even the HD when the WD disk was connected. I tried to connect the WD drive on another Mac with the same result. The MacBook Pro is running on MacOS X 10.11.2.
Any solution to keep my WD Disk ?

I have the same problem as Bernard_Gabadou! I recently purchased and began using My Passport Ultra in late October 2015–ONLY 5 months ago! I have a MacBook Pro running on MacOS X 10.11.3. I, too, got the message that it couldn’t find the WD Disk, and the Disk Utility was not able to help me either. I need answers. I’d hate to think I was out the money after less than 6 months of use!

I recently purchased and began using My Passport Ultra in late October 2015–ONLY 5 months ago! I have a MacBook Pro running on MacOS X 10.11.3. I, too, got the message that it couldn’t find the WD Disk, and the Disk Utility was not able to help me either. I need answers. I’d hate to think I was out the money after less than 6 months of use!

Early 2008 iMac running OS X 10.11.3 and I have the same problem.