Please can someome help. I bought a WD My Passport for Mac just over a week ago. When I connect the drive to my MacBook Pro running OS X Yosemite - it reports that the back up failed and when I try and run diagnostic ‘Complete Drive Test’ from the WD Drive Utilities - it takes a long time on 10% then comes up with ‘Cancelled’. I contacted WD support - and was advised the drive might be corrupt and to re-partition it - but the link I was sent did not give an option for OS X Yosemite - and when I looked at other OS X options - it was very complicated and confusing for an non-IT trained person. This drive was not cheap - and I am very disapponted at the trouble and stress it is causing. I am regreting purchasing this!