Rated 4 out of 5 stars

This solution by Sebastian it works:

When I close Thunderbird and under
"C: \ Users \ * username * \ AppDataLoca \ Thunderbird \ Profil \ * profilname \" delete the folder "StartupCache" and restart Thunderbird everything works normally again. Until I close Thunderbird again and restart ... then the problem starts again.

After reinstalling Lightning 68.4.2 it works fine again. No missing calendards and all calendar entries are back again and I can edit them.

Thank you Sebastian!!

Remember, Lightning 68.4.2, not the last one.

This user has a previous review of this add-on.

Rated 5 out of 5 stars

In my case, to solve thunderbird compatibility with google calendar...
I just closed thunderbird, adn removed the "calendar-data" and "startupCache" folder... and after I restarted thunderbird again!

Rated 4 out of 5 stars

Great tool but I had the same problem as dbstraffin on March 6, 2020. Same solution.

Thx, dbstraffin for figuring that out!

Rated 1 out of 5 stars

Lightning was a really good calendar application... before.
Now, I can't use it anymore, cause calendars are not listed, events are grey (or blank...).
It's really a shame.
Thunderbird 68.5.0 64 bits, on Ubuntu and Windows

Rated 4 out of 5 stars

I was having the issue with calendar not showing up properly (items and sync greyed out, no calendars listed).

I could get the calendar to work correctly by killing TB (pkill thunderbird) and starting it back up, but a normal shutdown would cause the calendar to be messed up again.

What finally fixed it for me was starting TB in safe mode and resetting toolbars and controls:
https://support.mozilla.org/en-US/kb/safe-mode-thunderbird

Rated 4 out of 5 stars

Wenn ich Thunderbird in Windows starte über
"thunderbird.exe -purgecaches" dann funktioniert es jedes Mal.

Wenn der Cache aber nicht gelöscht wird, dann habe ich einen leeren Kalender. Die Einträge vom "provider for google calendar" werden zwar angezeigt, jedoch sind diese alle "weiß" und nicht editierbar.

This user has 2 previous reviews of this add-on.

Rated 1 out of 5 stars

version 68.5.0
1st restart after upgrade -works well
2nd restart - no data in widgets

error console after clicking calendar icon:
viewNode is undefined calendar-views-utils.js:524
getLastCalendarView chrome://calendar/content/calendar-views-utils.js:524
openTab chrome://lightning/content/messenger-overlay-sidebar.js:64
openTab chrome://messenger/content/tabmail.xml:624
oncommand chrome://messenger/content/messenger.xul:1

EDIT: Fix from : https://addons.thunderbird.net/cs/thunderbird/addon/lightning/reviews/1161410/
does not fix unresponsive calendar UI, for example it is not possible to create new event:

An error occurred executing the calendar_new_event_context_command command: [Exception... "[JavaScript Error: "currentView(...) is undefined" {file: "chrome://calendar/content/calendar-common-sets.js" line: 293}]'[JavaScript Error: "currentView(...) is undefined" {file: "chrome://calendar/content/calendar-common-sets.js" line: 293}]' when calling method: [nsIController::doCommand]" nsresult: "0x80570021 (NS_ERROR_XPC_JAVASCRIPT_ERROR_WITH_DETAILS)" location: "JS frame :: chrome://global/content/globalOverlay.js :: goDoCommand :: line 101" data: yes] globalOverlay.js:104
goDoCommand chrome://global/content/globalOverlay.js:104
oncommand chrome://messenger/content/messenger.xul:1

Rated 5 out of 5 stars

Muy buena

Rated 1 out of 5 stars

Calendar has changed.
No boxes around days (month view)
No colors
No way to scroll months.
What is going on?

Rated 2 out of 5 stars

On my PC it's completely broken with Thunderbird 68.4.2. My calendar list is gone. Entries are still there but without any color and the UI is not responding.
On my Laptop it works though. Same version, same set of calendars (some Google calendars, some CalDav).

Edit:
It's really strange. Just updated to 68.5.0. Directly after restarting Thunderbird to install the update, Lightning worked again perfectly. After a second restart, I have the same issues as before.

This review is for a previous version of the add-on (68.4.2). 

Rated 1 out of 5 stars

After updating to Thunderbird version 68.4.2 all my Lightning calendars seem to be gone, I have a completely empty calendar. I tried to remove Lightning but it won't be deleted.
I have used Lightning for a couple of years but apparently the time has come to say goodbye to Lightning. I am not happy with this rude farewell, not at all.

This review is for a previous version of the add-on (68.4.2). 

Rated 1 out of 5 stars

Either Thunderbird 68.4.2 is broken or Lightning is broken in Thunderbird 68.4.2. Lightning causes Thunderbird 68.4.2 to hog resources, won't load any of my calDAV calendars, won't let me add calendars, and won't let me sync calendars. Thunderbird has a continuously spinning progress indicator if Lightning is installed and MacOS reports high power and CPU usage.

This review is for a previous version of the add-on (68.4.2). 

Rated 3 out of 5 stars

Version 68.4.2 of lightning causes Thunderbird freezes :( I'm fond of this extension, but please give a solution for this issue : my company works with it for years and the current is a really bad thing for us ! So 3 stars unstead of 5 !

This review is for a previous version of the add-on (68.4.2). 

Rated 2 out of 5 stars

Thunderbird 68.4.2 is not compatible with lightning. Which is quite a niusance, to be honest.
But the Provider for Google Calender does neither, so ...
Just bad luck that I need the calendar in my mail client, I guess.

This review is for a previous version of the add-on (73.0b1). 

Rated 1 out of 5 stars

Current Version (68.4.2) does not update the daily overview in the Thunderbird main window. It is stuck on the day Thunderbird was last started. Have to restart Thunderbird each day. Very unpleasant and new behaviour.

This review is for a previous version of the add-on (73.0b1). 

Rated 2 out of 5 stars

Monday, Feb 3, 2020 (or should I say “Monday 3 févr. 2020”): the language still breaks each time Thunderbird is updated. Deeply irritating.

This review is for a previous version of the add-on (73.0b1).  This user has a previous review of this add-on.

Rated 4 out of 5 stars

Après dernière mise à jour de Thunderbird (sur linux Kubuntu 18.04), mon agenda est en lecture seule et si je décoche cette propriété, je ne peux éditer les événements. Version Thunderbird 68.4.1

This review is for a previous version of the add-on (73.0b1). 

Rated 4 out of 5 stars

I'm on lightning 68.4.1. I use it to synce my addressbook from cardbook 43.7 (over Nexcloud), both on thunderbird 68.4.1.
A minor issue is, that the word "Cumpleaños", in Spanish, is passed from cardbook to lightning as "Cumplea�os". Any idea how to fix it?

This review is for a previous version of the add-on (73.0b1). 

Rated 5 out of 5 stars

Le souci signalé hier a été résolu et aujourd'hui, Lightning fonctionne parfaitement avec Thunderbird 68.4.1 et la synchronisation OwnCloud. Un grand merci aux développeurs pour leur rapidité !!!!

This review is for a previous version of the add-on (73.0b1).  This user has a previous review of this add-on.

Rated 2 out of 5 stars

Since the automatic update of Thunderbird to 68.4.1 version, Lightning stopped functionning. The add-on is still there but it is impossible to add a new event and the events registered before the update just disappeared. I tried the safe mode, to delete lightning and add it again from the add-on website, delete Thunderbird and install it again. Nothing worked.
It is really a pity, I was using Lightning a lot. Hope this problem can be fixed very soon.

This review is for a previous version of the add-on (68.4.1).