As stated, I just bought the WD My Book Duo 4TB and formatted the drive to HFS+J so it works with a Mac.
Drive partitioned in 5 partitions and all works well with the Mac in Finder / copying / backup Time Machine.
But when I want to use Smartware for Backup utility it opens and states my internal disk BUT nothing else ? No external WD Duo is showing in the software. Is Smartware for Mac incompatible with El Capitan ?
Help is wanted.