Thunderbird 91 forgets default calendar

Many people in Support Forum are reporting problems with a 'blank' calendar.
This may be google or other imported calendars, but it may also be the default Home calendar.
Sample list:
https://support.mozilla.org/en-US/questions/1347913
https://support.mozilla.org/en-US/questions/1347467
https://support.mozilla.org/en-US/questions/1347710
https://support.mozilla.org/en-US/questions/1347772

There are indeed many reports of issues, even just in the last couple days. Perhaps these need mention in a version 91 FAQ?

https://www.reddit.com/r/Thunderbird/comments/p7y07r/gmail_calendar_and_contact_sync_in_thunderbird_91/
https://support.mozilla.org/en-US/questions/1347759

Seems to me, the problems are very likely about provider for google calendar, and potentially other add-ons being incompatible.

Seems provider for google calendar is falsely claiming compatibility with 91? Can we disable in that case?

(In reply to Magnus Melin [:mkmelin] from comment #3)
> Seems provider for google calendar is falsely claiming compatibility with 91? Can we disable in that case?

Done.

*** Bug 1726483 has been marked as a duplicate of this bug. ***

So,
    Will the issue Google Calendar be 'fixed' in a subsequent release, and would someone be kind enough to notify me( and everyone else) :-) ?

and to repeat
a welcome addition to Bugzilla would be a check box to 'opt in to email notifications' when someone posts a new comment !

:-)

For the add-on, that's up to the add-on author. Thunderbird core can access google calendars just fine.

Isn't the default for bugzilla to send you emails on comments? If it's not sending, see your bugzilla account page and make sure you opt in for it.

Howdy Magnus, John et al
                           As I reported in a another Bug, concurrently that John responded to:
                          When I downloaded and upgraded from V78 to V91 my Calendar and subs( 3 of them were all LISTED , but no data was displayed)
There were 'Enable' buttons next to each sub calendar and I clicked each to no avail......rebooted , retried multiple times.
I had to use W7 System Restore to bring me back to V78 and get my Data back

So.......when this is Fixed....please advise so I know I can update to V91 or?
Thank you

If I HAVE to renter my Calendar(s) manually....please let me know !

PS I see Email Preferences
Can you kindly instruct me on how to be included in any updates for ONLY this BUG !
I'm just a USER /reporter for this bug !
https://bugzilla.mozilla.org/userprefs.cgi?tab=email

thank you

(In reply to Matt Miller from comment #8)
> PS I see Email Preferences
> Can you kindly instruct me on how to be included in any updates for ONLY this BUG !

"ONLY" is not easily possible. (But you are only CC on two bugs so I fail to see the concern about getting mail for other bugs)
* Go to https://bugzilla.mozilla.org/userprefs.cgi?tab=email
* click "enable all bugmail"
* go to the bottom and click "submit changes"

> please advise so I know I can update to V91 or?

When you see an offer **FROM THUNDERBIRD* to automatically update. We can't predict when that will be.

But none of this helps you with https://github.com/kewisch/gdata-provider/issues/194 You'll just have to wait and check when the author makes the new version available.

Thank you Magnus and Wayne.........
      I'm a little 'gun shy' and I'm happy with V78
so Maybe I'll stay put for awhile or until Gmail doesn't 'like' the Security in v78

PS the only Lightning addon I have that WAS needed for my Calendar is " Provider for Google Calendar"
Are you now saying that that add on is NOT needed anymore, and IS my problem?!

Provider is not needed for handling calendars anymore. If you use tasks, for those you need the provider since google doesn't expose them in a standard format.

(In reply to Matt Miller from comment #10)
> Thank you Magnus and Wayne.........
> I'm a little 'gun shy' and I'm happy with V78

91 does have a lot of things to like (once you find them)

> so Maybe I'll stay put for awhile or until Gmail doesn't 'like' the Security in v78

It is not the security in Google you need to worry about, it is yours. See https://www.mozilla.org/en-US/security/known-vulnerabilities/thunderbird/

> PS the only Lightning addon I have that WAS needed for my Calendar is " Provider for Google Calendar"
> Are you now saying that that add on is NOT needed anymore, and IS my problem?!

That would be the case. It has not been needed for some years really. I have been struggling since about 2012 to understand really what the provider offers that is not available using caldav other than the simplicity that the Thunderbird 91 inbuilt calendar detection now provides.

This blog post in 2013 is about Google caldav and Lightning and was written by the guy that maintains the gdata provider. https://blog.mozilla.org/calendar/2013/09/google-is-changing-the-location-url-of-their-caldav-calendars/ so it has not been needed since then at least.

Thank you again Magnus
     I had no clue that TB was under attack........
but having said that................what I was referring to is to be able to use TB with Gmail

One has to set Gmail to ALLOW for a 'Less Secure App' !
And even with that...........if one doesn't keep up with the TB updates, then one can find themselves not being able to reach the gmail server
because gmail has 'changed' their Security Protocols!

Is there any consideration being made to make TB secure enough in Gmails terms, to make it 'work' without having to tell gmail its a 'less secure app' ?

I believe it mostly goes away if you move to OAuth2 authentication (which is the default).
They may still try to scare you into using their web services... but what can we do about such marketing ploys.

(In reply to Matt Miller from comment #13)
> Is there any consideration being made to make TB secure enough in Gmails terms, to make it 'work' without having to tell gmail its a 'less secure app' ?

This is a Google/GMail thing, not so much a TB thing. Google/GMail would LOVE for email to just die and / or have their customers move to Webmail through a browser. It's a control thing. IMHO, Google CONSTANTLY wants to undermine established standards and move users away from ANYTHING that takes control away from Google's product and puts full control in a user's hands.

The whole "less secure app" is a marketing scare tactic by Google to make users think something that is perfectly secure is not. It's the method of access they're trying to hamper. I mean, why else would you have to flip a switch in GMail "Settings" through the web UI in order to access your IMAP/POP3 with a 3rd party client yet the GMail Android app happily access your IMAP mail without needing to flip said switch? Totally sus! Just sayin'.

(In reply to Magnus Melin [:mkmelin] from comment #14)
> I believe it mostly goes away if you move to OAuth2 authentication (which is the default).
> They may still try to scare you into using their web services... but what can we do about such marketing ploys.

+1

This is issue is not just a gmail google issue.
The 'Home' calendar is also lost. People are needing to do all sorts of work arounds - assuming they still have a backup.
eg: https://support.mozilla.org/en-US/questions/1347913#answer-1437750

Confirm, it occurred using TB internal calendar (formerly Lightning) not any external calendar.

Reinstalling TB 78, restoring profile, then exporting calendar and importing that into TB 91 recovered it.

It's an update problem.

Richard

I have created a test profile in TB78 with
- gmail account
- google provider with 5 calenders
- local home calendar

I upgraded that profile to TB91 and home calendar was available, google calendar where disabled (as the provider is not compatible with TB91). I also tried to add entries to my home calendar and everything worked as expected.

@rich & @anje (regarding broken home calendar after upgrade):
- What other add-ons have you installed during upgrade?
- What OS are you on?
- Are you able to provide steps to reproduce this, starting with a fresh TB78 profile and prepare that in a way that an upgrade to TB91 breaks the home calendar?

John,

Add-on's (Note, only using internal calendar, never used any ext calendar)

Signature Switch, Quote Colors, Remove Duplicate Messages

OS: Win 10 21H1 (up-to-date)

"Home" calendar is listed but all contents are blank after upgrade. Can't export calendar.

Tried the upgrade again (restored profile from backup/reinstalled TB 78). Same issue

Restored profile from TB 78, exported calendar.

In TB 91 deleted Home cal, imported calendar as new name (would not let me use Home)

I did not create a new profile or calendar and try to upgrade using that as the TB 78 profile and calendar were fully functional and I needed all the data

Richard

I created a fresh 78 profile, installed the 3 add-ons, put some events in my home calendar, and upgraded to 91. Everything works.

Richard, could you do the following for me?
1. Create a fresh TB78 profile
2. Setup your imap account
3. Install the 3 add-ons
4. Import the calendar which you had extracted from your backup
5. Load the profile with TB91

What happens?

(In reply to Matt Miller from comment #13)

> One has to set Gmail to ALLOW for a 'Less Secure App' !

No one does not! Thunderbird has supported oAuth authentication for Google for some time now. IMAP/SMTP since Thunderbird 40 and POP since Thunderbird 74.

> And even with that...........if one doesn't keep up with the TB updates, then one can find themselves not being able to reach the gmail server
> because gmail has 'changed' their Security Protocols!

That is always going to be a possibility. But oAuth makes it less likely. There was an issue on the 68 release for instance, Bug 1592407

(In reply to John Bieling (:TbSync) from comment #21)

John, I'm out-of-town until late Monday and don't have the exported calendar file with me.

Richard
========================================

> I created a fresh 78 profile, installed the 3 add-ons, put some events in my home calendar, and upgraded to 91. Everything works.
>
> Richard, could you do the following for me?
> 1. Create a fresh TB78 profile
> 2. Setup your imap account
> 3. Install the 3 add-ons
> 4. Import the calendar which you had extracted from your backup
> 5. Load the profile with TB91
>
> What happens?

Dear et al
                re TB and Gmail and Goggle Calendar
I've been a Pro Guru and user for 26 years. When Netscape Browser and Mail came out 20+ years ago, I was one of the first users
I'm not a Programmer and I salute you for TB !!! !!!!!!!!!!!!!!!!!!!!!!
But, I'm not a slouch either.

I set up new machines and new users with TB all the time.
Even with OAuth in my experience, the ' Less Secure App ' BS is ALWAYS NEEDED !
With Outlook...its NOT !
With Iphone IOS Mail or Outlook IOS, there is NO Problem !

And, I disagree, that Google is trying to force users to use Webmail !
It just seems that Google doesn't like Mozilla !!!! ????

PS The auto config sometimes works and sometimes not ;-(
If not, I usually copy my TB settings using my oauth settings and my ports to get TB to handshake with Gmail

Be all that as it may........... If Outlook is 'excepted' by Gmail to work without the "less secure app' protocol
I'm just asking if its not to difficult, to make TB 'exceptable' to Gmail
If its too much of a hassle........Now that I know about the ' less secure app' HOOP, I can live with it!

And back to the Google Calendar
    I'm humbly suggesting, that why release a NEW TB version without a MESSAGE warning Lightning users to disable Google Provider if thats what is needed to make it work?!

Again....my HATS OFF to all you Programmers, as I've NO Programming Skills and I salute you, as I LOVE TB !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
THANK YOU :-) !!!!!!!!!!!!!!!

> And back to the Google Calendar
I'm humbly suggesting, that why release a NEW TB version without a MESSAGE warning Lightning users to disable Google Provider if thats what is needed to make it work?!

An updated version of the provider is in the making and it is now marked by the compatibility check add-on [1], that it is currently not compatible with TB91. So if you install that compatibility check add-on in your TB78, it will check for you if it is safe to update to TB91 or not.

[1] https://addons.thunderbird.net/addon/addon-compatibility-check/

General information: We will not be able to manually "convert" calendars created/managed by the google provider add-on (which is using a proprietary google API to get all the data, including tasks) to CalDAV calendars managed by Thunderbird directly (which does not support tasks, because Google does not provide that info via CalDAV). If you want to switch from one method to the other, you will have to do that on your own:
* Remove old google calendars
* Remove provider add-on
* Add google calendars as CalDAV

This is not really related to the upgrade from TB78 to TB91.

> Even with OAuth in my experience, the ' Less Secure App ' BS is ALWAYS NEEDED !

That is really not true. See the attached image below.

Created attachment 9238456
grafik.png

Access to Google from Thunderbird does not require a dedicated app password (a.k.a less secure app access).

HI again John
         Forgive my stupidity, but you're not saying that my Google Calendar in Google online has to be deleted? and then recreated?
You're just saying to manually remove then in TB, and then re-import them into V91 as Caldav
Correct?

And BTW....WHY?! Why not leave it as it was.....working PERFECTLY ?!

And John
     re 'Less Secure App' access or not to gmail via TB

Then I MUST be doing something wrong as I just set up TB on a W10 machine a month ago and GMAIL STILL required 'Less Secure App' setup
to make TB work !

I can't remember if I used auto config or I manually set it up?
I always use Auto config in TB or Outlook as of course thats easier!

So I don't remember if it was OAuth or not!
You were saying earlier that THAT is the issue?!

PS Just found this on Github
https://github.com/kewisch/gdata-provider/files/7071662/gdata-provider-91.0.0pre1.zip

After installing "gdata-provider-91.0.0pre1" my calendar is working again.

(In reply to Matt Miller from comment #29)
> PS Just found this on Github
> https://github.com/kewisch/gdata-provider/files/7071662/gdata-provider-91.0.0pre1.zip
>
> After installing "gdata-provider-91.0.0pre1" my calendar is working again.

That is not yet released and has a serious bug. Please remove it to. It has not even passed review!

I will get to your other questions later.

Hi John
             Yikes.....Seems to be working !!!

(In reply to Matt Miller from comment #31)
> Hi John
> Yikes.....Seems to be working !!!

It is your decision. I warned you. I cannot do more than that. I originally suggested staying on TB78 until an official version of the provider for TB91 has been released.

> Forgive my stupidity, but you're not saying that my Google Calendar in Google online has to be deleted? and then recreated?
You're just saying to manually remove then in TB, and then re-import them into V91 as Caldav
Correct?

Correct.

> And BTW....WHY?! Why not leave it as it was.....working PERFECTLY ?!

**If** you want to switch away from the provider to the built-in CalDAV support, you would have to do the listed steps. But I suggest to leave it as it was and just wait for the official version of the google provider for TB91.

(In reply to rich from comment #23)
> (In reply to John Bieling (:TbSync) from comment #21)
>
> John, I'm out-of-town until late Monday and don't have the exported calendar file with me.

I'm back...

Did that. 91.0.3 opens the calendar imported into 78.13 (was prev using 78.12 but it auto-updated on me...)

(Reminder) I'm using local calendars not net...

Richard

(In reply to rich from comment #33)
> (In reply to rich from comment #23)
> > (In reply to John Bieling (:TbSync) from comment #21)
> >
> > John, I'm out-of-town until late Monday and don't have the exported calendar file with me.
>
> I'm back...
>
> Did that. 91.0.3 opens the calendar imported into 78.13 (was prev using 78.12 but it auto-updated on me...)
>
> (Reminder) I'm using local calendars not net...
>
> Richard

Hm, so it is not something specifically IN that calendar that caused the upgrade to fail. I am running out of ideas.

Regarding google calendars: The google calendar provider for TB91 has just been released:
https://addons.thunderbird.net/addon/provider-for-google-calendar/versions/

That should fix all the google calendar related issues mentioned in this bug.

(In reply to John Bieling (:TbSync) from comment #34)
> (In reply to rich from comment #33)
> > (In reply to rich from comment #23)
> > > (In reply to John Bieling (:TbSync) from comment #21)

John,

> Hm, so it is not something specifically IN that calendar that caused the upgrade to fail. I am running out of ideas.

Maybe rephrase that...

Not something in the exported calendar but maybe...

Something in the references to the calendar (as opposed to the calendar data itself)

or

Export "cleaned it up" meaning there is something in the data, but it was skipped in the export...

Richard

Still getting reports relating to the Home calendar - loss of data upon update to 91 - not working:
https://support.mozilla.org/en-US/questions/1349601
User says:
> To start with, after the update my main Calendar has completely disappeared taking with it very important upcoming appointments. In addition to that if I create an event all the data entered does not appear in the relevant day in the calendar and it will also not allow me to import any future events from other calendars.

In addition to discovering Home calendar blank - people also reporting they cannot retain added events which is not the same as this bug but I'm offering that bug link: bug 1729664

Some positive update towards a possible fix...

(In reply to Richard Leger from comment #66)
> (In reply to Anje from comment #61)
> > The issue regarding Home default calendar has not been discussed very much.
> I have suggested some troubleshooting steps here... https://thunderbird.topicbox.com/groups/beta/T948a3b1f2f93c62f-M8a0edcecc8ee0e80939c3f8b/local-calendar-events-lost in an attempt to isolate the problem with home calendar and get possible errors in the console.

As per https://thunderbird.topicbox.com/groups/beta/T948a3b1f2f93c62f/local-calendar-events-lost, Dimas confirmed encountering the **home calendar event not showing** issue after upgraded from his latest 78 (78.9.1 64bits he thinks) to 91 stable (91.0 64bits). Installed manually over the 78 in Program Files TB folder. Locale *ca* for all version. On Windows 10 Pro 21H1 with the latest Windows Defender (no other antivirus).

Following my suggestions, Dimas seemed to have isolated the problem, after disabling/enabling again the local calendar while monitoring the error console, still no event shows but in the console the following error appears (same as reported in Bug 1729664 Comment 4):

````
TypeError: item.id is null (24 times)
CalStorageCalendar.jsm:2252:9
````
When trying to add an event, no additional error appears.

Using Firefox sqlite DB manager add-on (https://addons.mozilla.org/en-GB/firefox/addon/sqlite-manager-webext/), he managed to open a copy of the local.sqlite DB and run two SQL queries:

Searched for items with null id:
````SELECT * from cal_events WHERE id IS NULL LIMIT 100````
Found one and deleted it:
````DELETE FROM cal_events WHERE id IS NULL````

Saved the database, placed it back in TB profile.

He could then
- see the home calendar events again!
- sort his calendar event invites issue (https://thunderbird.topicbox.com/groups/beta/Tcee69c120cb7f65d)
- have new event created retained in new calendar (Bug 1729664 fix not yet applied)

While the above is a possible workaround, it may not be advised to fiddle directly and manually with the sqlite DB as it may cause loss of data and discrepancy in the DB.

@Geoff, put you in copy for your information as you may be the best placed to understand why some event are set without item.id perhaps... and possibly be able to **set a routine via a patch that could automatically re-assign an item.id to any event without item.id in the local.sqlite db cal_events table** (and elsewhere where applicable)? If that is possible... Unless event with item.id NULL are *ghost* events... maybe duplicate not (properly saved?) from other events with proper item.id?

Hope the above helps the dev team fix the issue and anyone encountering it.

Regards,

*** Bug 1734677 has been marked as a duplicate of this bug. ***

*** Bug 1735189 has been marked as a duplicate of this bug. ***

Anybody with this problem have calendar extensions along with "Provider for Google Calendar" or without it installed?

Try disabling them and see if it helps.

*** Bug 1735438 has been marked as a duplicate of this bug. ***

*** Bug 1735342 has been marked as a duplicate of this bug. ***

I've used the Home empty calendar sqlite manager fix in Support Forum and had positive result.
For those directed to this bug and need more info to fix go to this link:
https://support.mozilla.org/en-US/questions/1352939

I have tried the above presented by ToadHall and still no tasks appear but three out of so many. They do appear to be within the local.sqlite file when opened in notepad (see bug 175342 - mine, for all details and attachments), but are not appearing in the application no matter how I set the tasks filter. In bug 175342 I attached the actual full local.sqlite files from TB 78 newly installed and TB 91, so that you can see them in notepad also along with screenshots. I seem to have main calendar, but not tasks. Thank you and I look forward to hearing from you.

(In reply to <email address hidden> from comment #74)

Bug 175342 seems unrelated, no attachment and was last updated 13 years ago... were there a typo in bug number you refer to?

So sorry, yes, bug is 1735342. Thank you!

I have also tried ToadHall solution, with no luck; calendar is still empty.

(In reply to spikeevans from comment #77)
> I have also tried ToadHall solution, with no luck; calendar is still empty.

I had removed the storage.sdb file to be able to add new events to the empty calendar; when I restored storage.sdb; this worked for me. Thanks much

(In reply to spikeevans from comment #78)
> (In reply to spikeevans from comment #77)
> > I have also tried ToadHall solution, with no luck; calendar is still empty.
>
> I had removed the storage.sdb file to be able to add new events to the empty calendar; when I restored storage.sdb; this worked for me. Thanks much

Did you get tasks or do you not use tasks?

I didn't have any tasks.

Am going to try this again (comment 78) after I re-install TB 78.1. My separate installation of TB 78.1 auto-updated to TB 91.2.0 at some point without my knowledge (note there are *no addons installed at all*) and *home calendar and tasks lost again* in that installation now. I am sure they are in the local.sqlite file as before, but not showing for whatever reason. Other calendars appear unaffected, still seem to have all events in them. No add ons, I am not syncing with any other calendars or applications. Will repeat steps as I did before to install TB 78 and remember this time to tell it not to update, set up bare profile with no email, etc., just calendars.

Before I realized the update had occurred, did try pasting in storage.sdb from a 09/22/2021 backup file, TB version unknown, with no showing tasks changes. Confirmed by changing task filtering several ways.

Note 1: Have installed TB 78.13 and imported .ics calendar into home calendar. All events and tasks show up like a champ. (No email set up, no add ons, just bare.)

**Note 2: Also installed clean TB 91.2.0 and when I tried to import .ics calendar, it appeared to just stall on "loading items" - see screenshot. Only took seconds in 78.13. Should I wait longer? Why will it not import the .ics? (exported in this format from TB)**

Note 3: Part of the problem with the TB 91 update could be the advice to import csv calendar as I opened this file by itself and noticed that it has lost a ton of data - those tasks I showed in file uploads "Call Union..." are not in the .csv.

Just performed another previous step, removed Calendar-data and prefs.js files from new clean TB 91.2.0 and pasted in those files from working TB 78.13 and VOILA! Main calndar events and tasks appeared!
So, why will these not show with the same files in the updated version of TB 91.2.0. Must have had something to do with previous addons now disabled and removed?

So, how do I move on forward from here in the most successful fashion? Updated TB 91.2.0 version has all of my email folders, etc., but no tasks and clean TB 91.2.0 has all of my tasks, but no email folders. What's the best way to get both in one, please?

Created attachment 9246025
TB 91-2-0 stalls on import of ics 2021-10-14 507pm.pdf

I have attached complete screenshots of all files in each version of TB 91.2.0, updated version and clean new version.

Created attachment 9246026
Clean TB 91-2-0 profile files screenshot 2021-10-14.pdf

Created attachment 9246027
Updated TB 91-2-0 profile files screenshot 2021-10-14.pdf

TB 78.13 clean bare profile with calendar and tasks showing updated to 78.14, restarted successfully with no issues, data appears intact.
TB 78.14 clean bare profile with calendar and tasks showing updated to 91.2.0 (next update offered in help/about), restarted successfully with no issues, data appears intact.
Update without addons wonderful regarding calendar and tasks. Again, though, if I set up my email in this or the clean 91.2.0, my email folders will not be there, correct? So, how do I get them over here, ideas, please?

Although ToadHall 's solution brought back my calendar, I'm not getting any notifications of events. I have check that thunderbird preferences are all set to do notifications.

Hmmm, I am getting reminders for previous events so far. Just set a new test one to see and that worked as well. However, as this step alone did not work for me, after I did it, I also did that to a local.sqlite in a back up file, then took the entire Calendar-data folder with this local.sqlite file within it and the prefs.js file (following another recommendation) and pasted it into TB 91. That seemed to work wonderfully, though my tasks did not all appear.

Odd, I am finding that neither the separate TB 78.13 updated to TB 91.2.0 bare profile nor the clean TB 91.2.0 want to import .ics calendars although they see that format for import and they will export to that format?! They just sit and spin.

(In reply to <email address hidden> from comment #81)
> **Note 2: Also installed clean TB 91.2.0 and when I tried to import .ics calendar, it appeared to just stall on "loading items" - see screenshot. Only took seconds in 78.13. Should I wait longer? Why will it not import the .ics? (exported in this format from TB)**

That is likely due to Bug 1727938 where calendar failed to import because it contains tasks.

I have the main/ home calendar that had the associated tasks showing in these two new installations which appeared after pasting in back up calendar-data folder and prefs.js file. They however, will not import the other three calendars, at least one of which only has events, no tasks.

My original installation (a third) which is original installation at least 8 years old progressively updated, had incompatible addons now disabled and removed, has all calendars and events, but not the tasks. I will not use addons moving forward as this has been a bit of a disaster and also no longer seems needed. I really love Thunderbird email, calendar, and tasks. I am trying to get one version that has everything, all calendars, all tasks, all email folders.

(In reply to Richard Leger from comment #91)
> (In reply to <email address hidden> from comment #81)
> > **Note 2: Also installed clean TB 91.2.0 and when I tried to import .ics calendar, it appeared to just stall on "loading items" - see screenshot. Only took seconds in 78.13. Should I wait longer? Why will it not import the .ics? (exported in this format from TB)**
>
> That is likely due to Bug 1727938 where calendar failed to import because it contains tasks.

Well if the calendar you are trying to import only contains events (no task) it should work in theory.
Also are you sure the the calendar contains no tasks? Have you open the .ics file in a text editor and make sure no VTODO appears listed?

Was the .ics file generated via a TB export?
Is it well formed (https://icalendar.org/validator.html)? Could it be incomplete due to something happening during export...
I suppose yes because they seems to import fine in 78.

You mention it says "loading items" have you tried to wait a long time, even half an hour or more and see if the calendar gets loaded?
Could TB be doing it but at a very very slow pace?

Moving manually Calendar-data and pref.js is not without risk especially if from a different profile because calendar are affected IDs and any mismatch may cause items to disappear(or not appear)... Maybe also try to disable the calendar and re-enable it, that may refresh local calendar... sometime artefact appears due to the offline support... mainly with network calendars...

Are all your calendars local calendars? If your calendars are network calendars, instead of using export/import, it would be better to re-set them up as network calendar in the new profile and re-sync them from the server...

What I would suggest is to re-test import in 92.2.0 (or which ever is the last ESR) with the .isc file you could import in 78... in a new empty profile with only one calendar in it. Disable the calendar. Open the error console (CTRL+SHIFT+J), clear it by clicking the trash icon. Enable the calendar. Then run the import. Do any error appears in the console?

I got my calendar entries to re-appear after upgrading from 78.14.0 (64-bit) to 91.2.0 (64-bit). Win 10 21H1. On 78.14, I deleted the few tasks I had as per the above remark, and exported the calendar to Home.ics. After the 91.2 upgrade, my Home calendar was empty. I then added a new local calendar Junk1, and then successfully imported the Home.ics file to Junk1. I have only ever used one local calendar (Home) for years now. And yes, I am one of those errant profile file replace folks as I replicate my email from machine to machine (and from Linux to Windows a while back).

I am also now able to add calendar entries to Junk1, and they do not disappear on a Thunderbird exit / reload (as they did before when my Home local calendar had no entries after the 91 upgrade). And add new tasks. Events and tasks added to the Home calendar (when Junk1 is hidden) still disappear on a reload.

If I try to import the same Home.ics file to the empty local Home calendar, the import dialog shows no progress what so ever (stalls) after selecting 'Import All'; and selecting an 'Import Event' also stalls. By stalling, I mean the 'Import All' button becomes washed out, and the progress bar shows no activity. Importing into the Junk1 calendar happened in like 3 seconds. So I don't think it's a performance thing. Also based on watching the memory and CPU activity of Thunderbird in the Task Manager over like 20 min, just in case.

So how do I move all the Junk1 calendar entries back to my local Home calendar please?

This issue is closed for me. I uninstalled 91.2.0, deleted the Roaming>Thunderbird directory, and re-installed 91.2.0. I was then able to import my 78.14.0 Home.ics file into the default Home calendar. Then I just had to re-add my few tasks. And also import my address book .csv files. And copy in all my years of saved Local Folders.

Rather a pain to re-create my email accounts and set all the preferences like I wanted them, but now I have all that documented. Thanks to Richard for the hint on deleting the VTODO entries. That .ics file did not import; it just completed this time with no entries in the Home calendar. My lesson learned was to back up my calendar and address books before an update (or a new install), empty my inbox to a Local Folder, and to stop overwriting the preference files, etc. Back on the normal update path now, and happy to be using Thunderbird.

I am afraid that if I enter manually all of my tasks, I will have issues going forward if I use the original installation of TB that has been gradually updated.
*How can I get my email folders and address book into the clean install of TB 91.2.0, please? My home/ main calendar and tasks are showing in this one and, most importantly, it has never had any addons installed within it.

(In reply to <email address hidden> from comment #96)
> *How can I get my email folders and address book into the clean install of TB 91.2.0, please? My home/ main calendar and tasks are showing in this one and, most importantly, it has never had any addons installed within it.

This forum is specifically for reporting bugs and providing information regarding that bug. It is not a Support Forum.
Please create a question regarding this request for Support in the Thunderbird Support forum and then post a link to it in this forum.
https://support.mozilla.org/en-US/questions/new/thunderbird/form

Apologies, but this bug report has become unmanageable - it is too difficult to distinguish what is add-on specific from what is not, and therefore progress is going to be impossible. So we are going to close this bug and start fresh in order to help move your individual issues forward.

If you have the provider add-on installed and you are still having trouble, please file an issue at https://github.com/kewisch/gdata-provider

If you do NOT have the provider add-on installed and you have a bug report that was duplicated to this bug, if you still have a problem then please reopen that original bug report.

Otherwise, if you have a problem and you do NOT have the provider add-on installed, please file a new bug report.

Wayne please re-read comment 67, this bug is clearly about local home calendar being empty following upgrade due to:

````
TypeError: item.id is null (24 times)
CalStorageCalendar.jsm:2252:9
````

add-on issue was a separate one that was early repored fixed via remove/re-add the add-on.

Both the following shall fix the issue a priori:

Bug 1729664 Comment 13
and
Bug 1727938 Comment 16

But it is hard to tell as the local home calendar empty issue upon upgrade is very hard to reproduce at will.
Only an affected user waiting for available update could confirm.

Also it remain unclear why the following error appeared in the first place nor if any of the patch would fix the issue other than a workaround/band-aid...

````jy
TypeError: item.id is null (24 times)
CalStorageCalendar.jsm:2252:9
````

(In reply to Wayne Mery (:wsmwk) from comment #98)
> Apologies, but this bug report has become unmanageable - it is too difficult to distinguish what is add-on specific from what is not, and therefore progress is going to be impossible. So we are going to close this bug and start fresh in order to help move your individual issues forward.
>
> If you have the provider add-on installed and you are still having trouble, please file an issue at https://github.com/kewisch/gdata-provider
>
> If you do NOT have the provider add-on installed and you have a bug report that was duplicated to this bug, if you still have a problem then please reopen that original bug report.
>
> Otherwise, if you have a problem and you do NOT have the provider add-on installed, please file a new bug report.

I did file a bug report purely regarding the Home Calendar
bug 1729664

The report was intially made because people found added events were deleted upon reopening. However, it was also discovered in these cases, that the Home calendar was empty. So in effect the problem was the update showed an empty Home calendar, so users tried to create an event and it would not stay if Thundervird was closed, so in effect a bug report already exists.

I suggest it is modified and used - if you feel a separate bug is required.

Some work was undertaken regarding the null entry - so it is possible the local.sqlite issue could have been resolved in bug 1729664 but I suppose time will tell if it works.

(In reply to Anje from comment #101)
> (In reply to Wayne Mery (:wsmwk) from comment #98)
...
> I suggest it is modified and used - if you feel a separate bug is required.
>
> Some work was undertaken regarding the null entry - so it is possible the local.sqlite issue could have been resolved in bug 1729664 but I suppose time will tell if it works.

How much time? I'd say it should be pretty quick to know one way or the other.

"FIXED/WORKSFORME/REOPEN"?

Certainly the blank calendar needs a solution if it is not yet resolved. I leave it to Richard and Anje to decide whether the bug continues and how to most efficiently proceed - whether this bug report should be reopened, or deserves a new new bug report.

As some work was undertaken regarding the null entry, I would suggest FIXED. If someone still encounter the calendar empty issue upon upgrade with newer version of TB then opening a separate follow up bug may be best to further investigate, referencing this bug for info. Unless anyone has objections and further useful feedback to help fix what ever remaining issue may have been left behind.