I’ve been submitting bugs far more often than usual since I moved to Ubuntu 12. Last week saw five or six in two days. At one point evolution gave me a segfault and on restart my Google sync’d calendar went to read-write only mode. I also couldn’t delete the calendar. Every time I started evolution I was given the dreaded unable to read a vEvent error.

No backend factory for ‘google’ of ‘VEVENT’

It probably was related to a crash. I was unable to find answers online for how to remove or repair the calendar so the fix for me was to manually edit the connection in gconf and then re-configure it in evolution.

WARNING: Since editing gconf is destructive be sure to have a backup of your evolution data before proceeding. You may lose everything if you do not back it up first.

To start, while not completely necessary, I reset evolution to its defaults to get a clean slate:

gconftool-2 --recursive-unset /apps/evolution

Next, run gconf-editor and navigate to “apps -> evolution -> calendar”. If you click on the “calendar” folder icon you should see “sources” in the right window under the name column.

Double-click on it and you will see the “Edit Key” window for /apps/evolution/calendar/sources.

Scroll through the values, find the Google XML statement, and click remove.

Then close down evolution.

evolution --force-shutdown

Now you should be able to start evolution, re-configure the Google calendar settings and continue using it.