The following bugs seem relevant: https://bugzilla.mozilla.org/show_bug.cgi?id=1560547 https://bugzilla.mozilla.org/show_bug.cgi?id=1596919 https://bugzilla.mozilla.org/show_bug.cgi?id=1583060 https://bugzilla.mozilla.org/show_bug.cgi?id=1600497 https://bugzilla.mozilla.org/show_bug.cgi?id=1600563 https://bugzilla.mozilla.org/show_bug.cgi?id=1606254

You're not alone and thank you John for pointing me here. (https://bugzilla.mozilla.org/show_bug.cgi?id=1600563#c5)

I've tried the suggestions listed here and none work for me. Current situation is - calendars appear without colours - some don't appear (mostly the web-based) or appear but cannot be modified (events can't be added or removed) - reminders mostly don't work (sometimes I get a random reminder but mostly they don't appear, so it's useless) - no events appear in the upcoming events space

Also randomly no calendars at all appear on starting TB (usually one or a couple of restarts makes them appear again), and/or I can't navigate the calendar.

It's been going on for a month and a half and it is very, very disruptive to work and personal life, to the point I've started using other calendars on my phone for crucial appointments. But it lacks integration and ease of use.

I hope a fix is forthcoming ! If anyone can point me to a reliable calendar on Linux I'd be willing to switch altogether, it is that annoying. Desirable features: -integrates multiple google calendars -integrates shared google calendars -syncs across platforms to Android tablet and phone -copies info to work offline (eg events set on a web-based calendar appear when I'm offline and reminders as well)

The link in the first line provides screenshots and description of the problem, I copy here some info about my system for reference (updated from first report, but still bugged as hell): Name Thunderbird Version 68.4.1 Build ID 20200110142707 User Agent Mozilla/5.0 (X11; Linux x86_64; rv:68.0) Gecko/20100101 Thunderbird/68.4.1 OS Linux 5.3.0-26-generic

Extensions Name Version Enabled ID Amazon.co.uk 1.1 true amazon@search.mozilla.org Bing 1.0 true bing@search.mozilla.org DuckDuckGo 1.0 true ddg@search.mozilla.org FileLink for WeTransfer 2.0.0 true wetransfer@extensions.thunderbird.net Google 1.0 true google@search.mozilla.org Lightning 68.2.1 true {e2fda1a4-762b-4020-b5ad-a41df1933103} Provider for Google Calendar 68.2.1 true {a62ef8ec-5fdc-40c2-873c-223b8a6925cc} Twitter 1.0 true twitter@search.mozilla.org Wikipedia (en) 1.0 true wikipedia@search.mozilla.org Auto Resize Image 1.1.0 false AutoResizeImage@gmail.com

Thanks Emmanuelle for the feedback. Looking at the details I can't say that this is exactly the same problem as that I'm experiencing, but differences may just be due to OS. One niggle: TB and Lightning are released together, so I would have thought you should be on Lightning 68.4.1, but there again I have no expertise for Linux and there may be a reason.

On the subject of the number of users recently affected by problems with Lg, I neglected in previous notes to point to the reviews of Lightning. Looking at reviews since TB 68, roughly half give 5 stars and half give 1. To me, such wild swings indicate "a very good product unfortunately malfunctioning for a lot of users". I agree that people are in general more often led to write a review to complain than to enthuse, but still. User "Chris" writing on Jan 16th in the [Edit] brings what I would call solid evidence of a problem that obviously has nothing to do with anything outside of TB and Lg.

I too have lost my Lightning calendar data I fully appreciate all efforts and experiments from all contibutors but I only half understand maybe 10 % of them

Just a quick update. TB 68.4.2 was made available on the release channel a few days ago. I updated today. No change as regards the problem discussed in this thread. However, I note that the problem does not occur at the first launch of TB after installing the update. I've noted that before. Unfortunately it comes back after exiting and re-launching TB a second time.

I am adding myself to this thread as a very interested party. I started this thread on 1/24/2020:

https://support.mozilla.org/en-US/questions/1278196?utm_campaign=questions-reply&utm_medium=email&utm_source=notification

Hi bob46, thanks for linking up. Looks like we're in the same boat so welcome aboard! I see that for you too, after updating TB, initially the problem seemed to have gone away but came back after the second restart.

One thing I find interesting is the way this problem affects different people at different times. It seems to have started with TB 68 but doesn't affect users immediately, in your case only with 68.4.1.

As you've seen there's a workaround that works for some people by restarting in TB safe mode and then restarting normal mode. Like after a TB update, this only works for one session, so you have to restart in safe mode every other time.

I had the same issue. I could get the calendar to display properly if I used "pkill thunderbird", the next startup it would work, but not after a "clean" shutdown.

Eventually I found that "Reset toolbars and controls" from safe mode permanently fixed it for me: https://support.mozilla.org/en-US/kb/safe-mode-thunderbird

Folks, we're making progress here.

Thanks dbstraffin for the info, and glad this worked for you. For me, initially it didn't, but it now has. AND I KNOW WHY, AND I CAN REPRODUCE THE BUG!!

Sorry to be so ecstatic but when you've been wrestling with a seemingly mindless problem for months and you finally solve it, that feels good as we all know.

After resetting toolbars and controls, and with the calendar working as it should, I naturally reset my toolbars and controls, and in particular three things, to the way I like them. These settings are:

• In calendar, multi-week view
• In calendar, list of entries at top of screen to show "Events in current view"
• In mail Today pane, categories "Tomorrow" and "Upcoming" are expanded.

To cut a long story short, it turns out that the "Events in current view" option for the list at the top of calendar, was causing the problem for me.

I can reproduce at will. All you have to do, to solve the problem, is to select another option, such as "next 7 days". No messing about with "safe mode" etc. Then just re-start TB in normal mode and the problem disappears.

I will post this info to the bug report

Thanks again to dbstraffin whose suggestion about resetting toolbars and controls pointed me in the right direction.

john.thompson & dbstraffin:

Thank you for figuring this vexing problem out! I greatly appreciate having a fix. For months, this problem has made maintaining my wife's business assignments calendar far more complicated than it needed to be. We had to use both Google and Outlook Calendar apps to get the same functionality that we had with Lightning and Provider before a software update of Thunderbird broke things.

john.thompson & dbstraffin - Thanks again!

Sorry folks but it still does not work for me, and my calendar is still a nightmare. I've tried changing the option in the Events pane but it doesn't seem to change anything (sometimes events show up there, sometimes nothing is there, so maybe that's indeed part of the problem) and the safe mode reboot doesn't help.

I'm frankly very annoyed and very disappointed that it's taking so long to fix. I have "solved" my problem temporarily by downgrading thunderbird to a version that is not broken by following this link: https://askubuntu.com/questions/1084391/how-to-go-back-to-previous-version-of-thunderbird-on-18-04 (to version 52.7.0 in my case)

It's at best a temporary solution as sooner or later one of the adds-on will fail to work and I'll be stumped again. Please, please, please developers fix the issue and don't let such a game-changing bug interfere with a great software !

Emma

@Emma: Yes, while the symptoms you described are similar to mine, they could cover a lot of calendar-related problems. I note in your screenshot of the error console that the "TypeError: currentView(...).startDay is null - calFilter.js:513:28" error is not present. This error is systematically present when I use the "Events in current view" option and it disappears when I choose another option, so it's likely a signal of the bug I've found a work-around for, and its absence, a sign that we're looking at different problems. However, there is an error in your console that I don't like at all, from "calStorageUpgrade". It might be worth searching specifically for info on that. Also, "Couldn't find customized Time Zone" and another time zone error. I would advise checking, and maybe resetting, your time zone in the Linux configuration. Unfortunately I'm ignorant of Linux and can't help much there.

I think it's probably wise to move the conversation back to your bug report, or start a fresh topic in this forum, as this thread, being marked "solved", is not going to get much attention from helpers. Let me know.

Ok will do, but just to signal something weird happened today. TB updated again on its own (even though I'd marked it as locked on the .52 version to prevent that, and even though I didn't upgrade any other package). I had lost all calendars so I removed both Lightning and Provider, restarted, installed Lightning, restarted, installed Provider, and lo and behold I got the calendars, their colours, and the access to the Web-based providers back. I have no idea why this small miracle has happened (I've done all those operations several times during the course of trying to fix the issue, this is starting to look schizophrenic (doing the same thing over and over again expecting different results)), or whether this will not break at the next reboot or when I go offline, but just to say some things don't seem purely rational (and if anyone has a good alternative to Provider/Lightning I'm all ears). Thanks anyway for suggestions (misery loves company. And tinkering).

@Emma Sorry for the delay in replying, things are a bit complicated in Europe right now... So which versions of TB & Lg are you on now? And what happened when you closed TB and relaunched?

Don't worry about the schizophrenia. Something will have changed, but you probably don't know about it!

On the subject of provider (for Google calendar) I recommend not using one at all. I find I have no need, all you need is to work through CalDAV, it's just that the configuration requires a little more work.

Matt, in his post in this thread Jan 11, kindly explained to me how to do this: "The accepted method of connecting a calendar from Google to Thunderbird is to use the caldav protocol directly. This does not access tasks, nor does it use addons.

1. Add a new calendar to Lightning Select on the network. 2. Select the format caldav 3. Enter your gmail address and the caldav endpoint for Google. being https://apidata.googleusercontent.com/caldav/v2/your-email-address/events

Where you replace your-email-address with your actual email address."

A major advantage is that it removes one (or two) add-ons. That allows the add-ons to be discounted as a possible source of the problem. It didn't help me with my problem but now we know why.

Slightly more subtle, is how to add read-only calendars from Google like public holidays of different countries, using this technique. I'll write it up but now I've got to go to supper.

Had the same problem. With me it was the ad blocker add on which was not compatible. Removing it did the trick.