Most likely a corrupted Zeitgeist database.
I recommend doing the following on the terminal:
killall diodon killall zeitgeist-daemon mv ~/.local/share/zeitgeist/activity.sqlite ~/.local/share/zeitgeist/activity.old.sqlite G_MESSAGES_DEBUG=all diodon
So what this does is closing the Diodon and Zeitgeist service, moving the database away and then starting Diodon in debug mode, so you can see what happens. Hope this helps.
Most likely a corrupted Zeitgeist database.
I recommend doing the following on the terminal:
killall diodon share/zeitgeist /activity. sqlite ~/.local/ share/zeitgeist /activity. old.sqlite DEBUG=all diodon
killall zeitgeist-daemon
mv ~/.local/
G_MESSAGES_
So what this does is closing the Diodon and Zeitgeist service, moving the database away and then starting Diodon in debug mode, so you can see what happens. Hope this helps.