Same experience here, with an external My Passport, 1 TB. Wierd, because my two main USB3 drives are working perfectly. I see nothing in system logs when attempting. Arrived in office to see error message about drive being removed but not properly ejected. Most recent backup was completed at am today. My passport has been connected via USB and used as time machine backup.

Then did a Repair and it came back into Finder. Did a reboot with it plugged in and Disk Utility found it again. I verified it, then it disappeared from Disk Utility. Luckily I used exFat format - so I can still get the data from Windows 8 so the data is fine. 1v1 lol mobileĮxtremly frustrated I have 2 itunes librarys and 2 iphoto libraries on this drive…. Now my Mac does not recognize the drive i can see it in disk utility but cannot do anything with it. I am having the same issue upgraded to Maverics on my Mac then as per your e-mail i uninstalled wd smartware. The hard drive is still under warrently, but thats not the problem, i need the data on this hard drive! Same for you. I went to plug it in to my MPB today and nothing happens, the light comes on in the hard drive and i can hear it running but it doesnt seem to mount on to my MBP, it doesnt show up in disk utilities either. I have a 2TB mypassport drive that i use with my macbook pro, its the one that fits in the rugged case and is USB 3.