Portable drive not seen on Mac

LRussoPhoto

Im having an issue with a portable drive. I plugged it in to my Mac, opened LR and started to import images. The drive was very slow to respond then froze. I closed LR and tried to eject but it wouldnt eject so I just unplugged. Now when I plug it back in it does not show up in finder. The light on the drive is flickering like it is working but the Mac doesnt see it. I went to my disk utility and I can see it there but when I click verify disk or repair disk it says file format not recognized. This happened once before but I forget what I did to fix it. Any ideas?

LRussoPhoto

issue resolved