Just happened to me last week. Unfortunately the only fix I was able to find was doing a factory reset and starting over. I usually save my configurations to a USB drive before I do any firmware upgrades so I can easily reload, and that came in handy.
The interesting thing was that after I did the factory reset, my firmware was upgraded, so it did indeed work. Sometimes the equipment will get mad and wont let you reset it unless you leave it unplugged for a few minutes.
