I have a very high tab count, and when restoring Firefox I usually get the "warning:unresponsive script" pop up. I press continue, it pops up again, I press continue again, and my tabs are restored. All is well. However, when I restarted Firefox today, it updated, and rather than the unresponsive script box, I get a blank pop up. I cannot do anything, and my tabs cannot be restored. I tried a refresh and a clean install, but that does nothing.