Upfront Editor won't load

After updating to latest version of Panino, the Upfront editor won't load. I've tried multiple times. I've disabled plugins. I've logged out and back in. I've cleared cache. The editor just loads and loads and loads. I've had the current window open for a little over an hour, and it still just says "The Upfront editor may take a while to load (especially first time), please hang in there " Anything I need to do differently? After more than two months kicking this theme around, I'm still at a loss. So many awesome features, but there always seems to be a profoundly large hurdle in place with regards to using the theme regularly. Any insight is much appreciated!