The developer has attempted to make setting up your Google Calendars in Lightning easier with the 1.0.x versions of Provider for Google Calendar. Unfortunately, this change may not work with certain Google Calendars. The new setup process simply wants the email address associated with your Google Calendar (instead of using the Calendar or Private addresses). While this worked for my main calendar directly tied to a real Gmail address, it did not work for my school calendar. My school calendar is tied to the domain of my college district (maricopa.edu) which uses Google API for email, calendar and other Google services.
The problem seems to be with the authentication process. When I access my school’s Gmail or other Google services via the web and use my school email address, I am redirected to the District’s sign-on page to authenticate on their AD server. Once I have successfully authenticated with the district then I am redirected back to the Google service I was trying to access. What happened in Thunderbird was when Lightning tried to connect to my school calendar Thunderbird popped up a window with the District’s signon page. I attempted to sign-in but when I clicked the button to submit, I would get a ‘Connection Timed Out Message’. I am guessing this has to do with the limited web browser abilities in Thunderbird.
There was a recent comment on the add-on page about using the caldav option and using an URL which contained your Gmail address. I tested this option by trying the URL (substituting my school email address for the Gmail address) in a web browser. I was presented with an authentication pop-up from I believe Gmail. I attempted to use my college district sign-on information, but it would not validate. In this case, I believe the problem was the validation was trying to take place with Google and not with the District. So that option doesn’t work either.
NOTE: On November 17th, Google changed the sign-on APIs which breaks version prior to 1.0.x of Provider of Google Calendar.
The good news is you can revert back to version 0.32 of Provider for Google Calendar by downloading the add-on here and then dragging the file into your Thunderbird’s add-on manager or in the Thunderbird add-ons manager click the gear button and select Install Add-on From File. The bad news though, is you will need to setup your broken calendars again. If it has been a while and you have forgotten how to do this, you will need your Google Calendar’s Private Address (XML) or if your calendar is public then the Calendar Address (XML). Follow the directions below to re-setup your Google Calendars in Thunderbird: Log in to your Google Calendar via the web (google.com/calendar/). On the left side under the heading My calendars, locate the name of the calendar you are setting up and on the right side of the name, click the down arrow then choose Calendar settings Towards the bottom of the Details screen click on the XML icon for either Calendar Address (use this if you have made your calendar public) or Private Address. Copy the link that shows in the pop-up box. Go to Thunderbird and open the Calendar tab. In the left side bar below the mini monthly calendar you will see a list of all your calendars. If any are grayed out, right-click on the calendar name and select Delete Calendar. From within Thunderbird go to File > New > Calendar… For calendar location choose On the Network. Then click Next. For format choose Google Calendar and then paste the URL from stop 3 into the Location field. Then click Next. Note: If you get an error that you are ‘already subscribed’ to this calendar you will need to make sure you deleted it as directed in Step 5 above. Now you will be asked to choose the title for your calendar as well as the display color for the events. Fill in this information and then click Next. Your calendar has been created! Click Finish.