USB drive not selectable

I've been wrestling with BE2012's backup-to-disk.  I had a disk configured and in the course of setting up this server I filled up that disk.  I wasn't able to purge the disk using BE so I removed it as a BE storage device, and reformatted the disk.  Now I'm trying to add it back into BE as a storage device.  When I run the Configure Storage wizard it won't give me that disk as choice.

The disk is bare.  What else to I have to do to get BE to allow me to select that disk as a backup-to-disk destination again?

Thanks

Bill