Calendar Management is now my Full Time Job...

For discussing the Mozilla Calendar, Sunbird and Lightning projects.
Posts: 262
Joined: April 23rd, 2011, 5:51 pm

Post Posted February 16th, 2017, 7:14 pm

Hello again,

Still no success, but please see my comments inline below:

mgagnonlv wrote:Hello,

I decided to bite the bullet and used my office calendar via its web interface to book a Google calendar. It works, but there are a few pitfalls along the way. If everything is set up correctly, then it works. Here are a few points to check.

1. My Google calendars are accessed via "Provider for Google Calendar 3.1". I don't think it is currently possible to use Google calendars otherwise (it used to be possible a few years ago). If you have set up a calendar as Ical, the calendar is set, but it will fail as soon as you want to modify it in Thunderbird/lightning.

I am using Provider 3.1
I am trying without success to use an iCal calendar newly set up in TBird. It keeps reverting to read only.
Are you suggesting that I use iCal, or another calendar option in TBird? If so, which option? Also, should I be using the Google iCal location, or the Google HTML location, or something else?

2. With Provider for Google Calendar, connect to your Google account and then to the calendars you want to use.

3. For each of your calendars (Google or otherwise), right-click on the calendar name and select "Properties".
In the properties, check your "email address" (second to last line – see note at the end).
I think that you can only accept events in calendars for which you have set an email address, as well as local calendars.

I have entered my non-google email address.

4. When someone invites you to an event, the blue line "Accept" appears. If you click to accept an event, then all calendars for which you have set an email address will be listed.

Sorry, but I don't understand your comment #4 above. Where would these calendars be listed?

5. Once you have selected a calendar, the event will be added to that calendar. An email confirmation may also be sent to the meeting organizer, depending on settings in about:config.


a. Some Google calendars don't have any "email address" settings. I have also read in the WIKI that only the primary calendar of an account can be configured to accept invites.

I have entered my non-google email address in the settings for what I now understand to be my "primary" calendar.

b. To enable automatic receipts when you accept and event or modify its details, visit the Provider's wiki page, and also read the accompanying warning.

I have turned on calendar.debug.logging and when I try to accept an invitation, the log shows this error[color=#FF0000]: Timestamp: 2/16/2017 8:46:20 PM
Error: An error occurred when writing to the calendar KSA-OLD! Error code: MODIFICATION_FAILED. Description:
Source File: resource://calendar/modules/calUtils.jsm -> file:///F:/Thunderbird/extensions/%7Be2fda1a4-762b-4020-b5ad-a41df1933103%7D/calendar-js/calCalendarManager.js
Line: 959.

Might you have an understanding of the meaning of that error?

Thanks for any further help on this,


Posts: 2
Joined: May 2nd, 2017, 5:28 am

Post Posted May 2nd, 2017, 5:48 am


I know it's a bit late, but we use google calendars to share appointments across 15 users at work and have a fairly stable setup so I thought I would see if I could assist.

We all run:
Windows 7 Pro x64
TBird 45.0
Lightning 4.7
Provider 3.1

We are careful to setup all machines to turn auto updates off so we can all maintain a stable setup and not have to worry about things crashing out every time an add on/TBird is updated. Hence why we are running an old release (when we update, I have to to go round all 15 machines and update them all within a basically I'm putting that off!)

We set up similarly to how you described but not using ICAL. So each user creates a Google Account (we actually share them all out to a central 'manager' calendar - which aggregates them all and makes them easier to add/remove from TBird as we can just add the manager and then tick/untick which individual users we want to see) and then everyone can view each other's that way but they cannot edit each other's appointments (they also don't need to know each other's passwords).

User A can add their own calendar directly (not via the manager calendar) so they can have read/write ability.

We do this by:
Choosing 'New Calendar...'
Select 'On the Network', then 'Next'
Click 'Google Calendar', then 'Next'
Type in '[manager calendar/personal calendar]' then 'Next'
A login prompt appears, so log in
Tick the box beside whomever you want to add, then 'Next'
Finally, click 'Finish'

This seems to work, populates with all appointments. Most features are cross-compatible, such as event privacy, re-occuring options etc. We have found that some phone apps mark appointments as 'tentative' as opposed to 'confirmed' and haven't found a way around that (the cheat is to modify userchrome.css so tentative appointments aren't shown at 0.5 opacity)

So that's our setup. Now to appointments and accepting invites - we invite people based on their work email address (not their GMail one) and when they click 'Accept' they are usually prompted to select which writable calendar they would like the appointment to be allocated to (as most people have at least a couple of calendars for personal/work or something similar). The appointment then appears and that's that. We have invited multiple attendants many times and they seem to work ok most of the time.

The exception to this is when appointments are changed - something along the chain doesn't like this. If we try to accept the change we usually get the error you described - Processing message failed. Status: [somethingicantremember]. I find we have to delete the original appointment from our calendar, and then we can accept anew from the updated invite. The host seems to have no issue amending appointments, this only seems to affect attendees.

Maybe that helps, maybe I'm just rambling. But if any of that made sense, hopefully it was useful! Let me know if you want any other details.


New Member
Posts: 1
Joined: May 3rd, 2017, 6:22 am

Post Posted May 3rd, 2017, 6:36 am

I too experienced calendar problems that started about a week ago, basically having lost the sync with my Google calendar. I tried many things to fix the problem, for hours. I deleted my most-used calendar and could not get it back; using the New Calendar option, it would never include the account I wanted to add among the calendar listings, so I could never select it. This is what finally worked for me (I'm using Windows 10). I made sure that I updated to the latest Thunderbird (52.1.0) and Provider (3.3). I went to add-ons and disabled Lightening and Provider and restarted Thunderbird. I then went to Tools>Options>Security>Saved Passwords and deleted all the entries associated with my target account. I believe this last step was the key. I then enabled Lightening and Provider and restarted Thunderbird. Several windows appeared that asked my to enter my password or click Allow, which I did in each case. I was then able to successfully get my calendar back by adding it with the New Calendar option.It took a few minutes to sync, but everything seems back to normal. I hope this helps someone else!

Posts: 262
Joined: April 23rd, 2011, 5:51 pm

Post Posted May 3rd, 2017, 8:00 am



The password suggestion got things working again.

Sincere thanks,


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