Wow it like i wrote this post myself you have EXACTLY the same experience as me, the only difference is it has worked on this macbook but seems to have stopped since Yosmite update!
I can only see the My Passport in the system report hardware tree, i also when trying to update the firmware got no device detected, and then was asked to accept the license agreetment and was told the device is locked and to unlock and click continue. Problem is I dont know how to get to a screen to unock it?
Any updates or further advice would be greatly appreciated, i have years of work documents and 23,000 photos on this device. I do have everything backed up to JustCloud storage so its not as much as a risk it would just be time consuming to get it all back onto a hard drive. Also all my time machine backups are on this drive!!!
HELP PLEASE :confounded:
