Can't read WD 2TB Harddrive on Mac, but works on AppleTV

Hi Folks!

I have a 2 TB WD external hard drive that’s filled with movies and connected to my 1.gen AppleTV.

A friend wanted to copy some of my movies, so I disconnected the hard drive and plugged it to my iMac coz it’s faster to copy the movies on my Mac instead of doing it on WiFi using Cyberduck. For some reason my Mac can’t read my hard drive anymore, but it did before. When I plug it back in my AppleTV i can access the drive from Cyberduck.

I have made a backup of all the movies using Cyberduck (took 2 bloody weeks to finish!), and when i tried to format the old hard drive from my Mac even that fails. I even tried to do it on a Windows PC, but it say the drive is locked.

Any ideas how I can fix this and read my hard drive form my Mac again? 

 

Thanks in advance :)