The WD update server is currently unavailable

I’m using an iMac running El Capitan. I’ve downloaded WD smart ware and am trying to backup up my WD MyCloud personal storage device. On the smart ware screen I can see the Home and Settings tabs but Backup and Retrieve I cannot access. I can’t get to the ‘Set Up Drive’ option os Settings either. When I select Update Software from the home screen I get the error message as in the title.
I have little technical ability but can generally find my way around, what do i need to do to get this working?

BTW TimeMachine no longer seems to work hence my moving to this solution.

Time Machine link to an existing network storage device may be brocken during the update to El Capitan, in the internet there are several similar issues documented. Delete the path to the NAS within Time Machine and re-setup it again, then it will work.

El Capitan seems to bring a lot of problems into a former stable system.

I don’t understand ‘delete the path to the NAS within Time Machine’ - there seems to be no facility to do this within Time Machine? All i can do within Time Machine preferences is to select a disk, or remove one. Is that the same thing? Opening Time Machine just gives me a screen full of previous snapshots

Sorry for not having found the right terms, I am not a Mac Pro; yes, delete the disk and re-setup it.