Rated 4 out of 5 stars

by Morgana on Oct. 27, 2014 · permalink

You have delete your Google calendar from Thunderbird and then reinstall it. See:
https://groups.google.com/forum/#!topic/provider-for-google-calendar/nSqra_q-zQ4

Probably a good idea to include information of this sort when releasing an update that requires user action.