Using WBFS for MacOS X but unable to detect my drive storage device on it!

Hello,
So I've been working on using the USB Loader in my Wii, and I finally reached the final steps until I faced a problem. I'm using a MacBook Pro and I downloaded WBFS to format my drive and use it on my wii, but even though I formatted the drive in the disk utility to two partitions with each one of them with the forum MS-DOS (FAT), but still when I open the application WBFS it wont detect the drive, I searched for a solution but still nothing helped so I was hoping I can find a solution or someone to tell me what to do.
Thanks.

Gotta do it on a PC, for some reason, the Mac version doesn't pick it up.