Led by https://bugs.launchpad.net/ubuntu/+source/unity/+bug/1250314/comments/2 , I tried 'rm ~/.local/share/zeitgeist -R', and that solved the problem for me.
Led by https:/ /bugs.launchpad .net/ubuntu/ +source/ unity/+ bug/1250314/ comments/ 2 , I tried 'rm ~/.local/ share/zeitgeist -R', and that solved the problem for me.