External Harddrive My Book Duo crashes my Mac – HELP

Hi
while transferring files onto MY BOOK the macbook pro crashed. When I restart the computer with the external hard drive, it immediately crashes. If I restart without the external drive, everything is fine. What happened? How can I fix the problem? Is the drive broken?

What happens if you connect your unit after your system has fully booted-up? Have you tried replacing your unit’s USB 3.0 cable? Do you have this issue with other USB 3.0 devices? Does the unit crash a different computer?