I disabled Google Provider which then allowed me to create an event successfully but I still cannot import a calendar

Please disregard my previous post. The Calendar still refuses to function.

re: I then re-added the dhallam@knology.net (what I am considering my Home) and got no information sync with my Google calendar on my cellphone.

That sounds wrong.

The 'Home' calendar is not a calendar which is linked to google or any other calendar. It is only shown in Thunderbird. It is the default calendar in Thunderbird. It does not 'sync' with anything. It has nothing to do with google.

So that would be created like this: Right click in the left pane in Calendar and select 'New Calendar' choose 'On my computer' and click on 'Next' Give it a name and I suggest 'Home' so you know it is an ordinary Thunderbird calendar. Email is usually set up to use the default account - select @knology.net email address. Do not choose gmail address if you use google calendars as that is a different type of account. click on 'Next' click on 'Finish'

Right click on new 'Home' calendar and select 'Properties' and make sure the top left checkbox is selected 'Enable this calendar' - click on OK.

The Birthday and Holiday and gmail address calendars sound like Google calendars, so they would need to be be created after adding the up to date addon 'Provider for Google calendar'.

Right click in the left pane in Calendar and select 'New Calendar' choose 'On the Network' and click on 'Next' select 'Google Calendar' and click on 'Next' select or enter gmail email address and click on 'Next' This then offers you a list of calendars you can subscribe to see. I do see a Birthdays and a Holidays calendar in my list as well as the gmail email address, so you would select all three. If you want to see 'Tasks List' then select that as well and click on Next.

I think I did what you suggested. I deleted my dhallam@knology.net (Home) calendar, then installed it. This time I called it a Google calendar. Now everything is working fine. I still don't understand why I was having no problems with thing the way they were until Thunderbird was updated to V 91.

I'm in Australia, I have 2xPC and 2xNobooks. All Win10. I have been using Thunderbird and Firefox for more that 15 years. Installing the latest update to ver 91.1 is an absolute disaster. Lost my calendar and cannot enter new events or tasks. everything disappears as soon as you close it. Reading through these articles it would seem that having a super-scientist degree is not going to save me figure out a solution. I tried all of them; even suggestions to follow an sequence in tools that does not exist. On the plus side, I only updated one PC, unfortunately my main one. I will not be updating the others. I've been reading all the comments and it seems the problem is growing as people update. Now I'm considering removing Thunderbird altogether. I cannot afford this ridiculous waste of time with what was once a trusted application which suddenly goes down the gurgler.

Thank you Thunderbird for making a forced update/upgrade that is a total FUP.

Tried several suggestions and now everything is corrupted. Ended up uninstalling Thunderbird altogether. After so many years with such a brilliant product I'm now forced to look for an alternative.

Seems to me Thunderbird is taking lessons from Microsoft as to how to take a great product and make it a terrible one. They did warn us they were moving to the dark side of things. Very disappointed. Will no longer recommend.

Tried several suggestions and now everything is corrupted. Ended up uninstalling Thunderbird altogether. After so many years with such a brilliant product I'm now forced to look for an alternative. Seems to me Thunderbird is taking lessons from Microsoft as to how to take a great product and make it a terrible one. They did warn us they were moving to the dark side of things. Very disappointed. Will no longer recommend.

Hi rick132 As a head's up, when you post a comment in someone elses question, you are sending that comment directly to that person. Your comment is of no help to them. This is not a chat forum for people venting their frustrations.

I note that you have not asked your own question on this topic - that would be the best thing to do. So when you create a new question re3garding this calendar issue, it would very helpful if you could supply some information such as whether this has effected the Home default calendar and/or Gmail calendar etc. I have been trying to gather information for developers to find out what is going on as it does not effect every one. I deliberately manually uninstalled version 78.14.0 and installed 91.03 with no issues.

It would also be helpful if you could supply images of the contents of the Error Console. Menu app icon > Tools > Developer Tools > Error console

It would be helpful if you could check whether the files still contain data, so we can find out whether this is a display issue or not. This is where the files are located, so please provide images showing the following. Menu app icon > Help > Troubleshooting Information Under 'Application Basics' - about 8th in list is Profile Folder - Click on 'Open folder' A new window opens showing the contents of your 'profile name' folder.

Click on 'calendar-data' folder to see contents. Make sure it is showing details so these column headers - Name, Date Modified, Type, Size Post an image

There should also be a 'backup' folder Click on the 'backup' folder to see contents Make sure it is showing details so these column headers - Name, Date Modified, Type, Size Post an image

Perseverance pays off. I uninstalled TB 91 on my main computer Then from one of my notebooks using TB 78 exported my calendar to an ics file. Reinstalled TB 91 on my main PC, imported the calendar from said ics file, restarted my PC and... nothing. UninstalledTB91 and reinstalled it, and everything came up. Why? No idea. But it did work and is still working.

Will not update my other devices; one lost working day was bad enough.

Worst SW updated ever.

All of this confuses me. I'm not using anything, but the "native", Lightning calendar. when I upgraded, to ver 91, I lost all my entries. My "birthdays" are still there, though. They must be in a file somewhere, so I think I could "import" the file, if I could find it. What is its name, and where is it located?

I followed Toad-Hall's suggestions, and here are the folder contents: Calendar-data:" Backup cache.sqlite cache.sqlite-shm cache.sqlite-wal deleted.sqlite local.sqlite local.sqlite-shm local.sqlite-wal

"Backup": local.v19.sqlite local.v20.sqlite local.v22.sqlite local.v22-1.sqlite

Now I need to know: If I want to import my old calendar data, which files should I look at, and will it work? Thank you all, in advance, for your gentle assistance, solving this frustrating problem.

Difficult to know exactly which file as I needed a image which showed all the modified and created file column headers. But from other info it would seem to be the backup folder local.v22.sqlite.

• AS previously - access the profile name folder.

• Exit Thunderbird if running....this is important

• Click on 'calendar-data' folder to see contents.

• click on 'backup' folder.

• Copy local.v22.sqlite from the calendar-data/'backup' folder
• Paste into 'calendar-data' folder, so it is in same place as  'local.sqlite'

• Rename 'local.sqlite' to say 'local.sqlite.bak' -  so nothing is lost.
• Rename 'local.v22.sqlite' to say 'local.sqlite' , so the backup has replaced the current.

• restart Thunderbird and report on results.

Whilst the files may seem to be of same size, at this point it is not known if there is some corruption in a file or whether code is causing inability to access and display. Thanks for trying this out as I'm trying to get feedback on whether this method actually works for those who have data stored but seem unable to access it. So your help is much appreciated.

Located some excellent feedback so try this:

• Menu app icon > Help > Troubleshooting Information
• Under 'Application Basics' - about 11th in list is Profile Folder - Click on 'Open folder'

A new window opens showing the contents of your 'profile name' folder.

• Exit Thunderbird if running....this is important

• Click on 'calendar-data' folder to see contents.
• Copy local.sqlite file and put copy onto desktop.
• In calendar-data folder - Rename 'local.sqlite' to 'local.sqlite.bak' - but if you already have this that's ok - just delete the 'local.sqlite' file.

Download install addon - Firefox sqlite DB manager add-on into Firefox browser.

• https://addons.mozilla.org/en-GB/firefox/addon/sqlite-manager-webext/

• Start the addon - you should see a new icon on the toolbar near the menu app icon - hover over icon and it will say SQLite Manager - clickon it.

Use addon to open the desktop copy of the local.sqlite DB

• drag the desktop copy of 'local.sqlite' into the opened addon.

run two SQL queries - you type this in the yellow area

Searched for items with null id: SELECT * from cal_events WHERE id IS NULL LIMIT 100

If you find any... So then use the following to deleted it: DELETE FROM cal_events WHERE id IS NULL

Saved the database file, 'Save' located at the bottom - save is usually saved in the 'Downloads' folder.

• Access the 'Downloads' folder to locate downloaded saved version of 'local.sqlite'.
• put the saved 'local.sqlite' back into the 'calendar-data' folder

restart Thunderbird and report on results.

I, too, had and to some degree still have this problem. With the TB 91 update which automatically happened earlier this week, it seems, my main calendar events and tasks disappeared. I have removed all Thunderbird add ons as I do not wish to experience this problem in the future and do not know if the missing calendar was actually associated with the incompatible add on to begin with.

I tried a number of things suggested including your local.sqlite sequence above. My main calendar, which is the one I lost data for, has retained what appears to be all of my information - I see some important reminder events in the future. I have been able to add an event and have it appear after restarting Thunderbird 91.

I have seen no mention of tasks here really. I use them quite a bit! Though I can now see my calendar events, I cannot see my tasks, but 2. I do not know why these 2 would appear and not the others. Now that I have done the above things, I can add a new task and it is still there after I restart Thunderbird 91. However, when I opened local.sqlite in notepad from my current TB 91 profile, my tasks appear to still be within the file when I use "find," and they also appear when I place the same local.sqlite file in the new Thunderbird 78.11 profile which I have installed in a separate directory per someone else's helpful steps. Why will my tasks not show in Thunderbird 91? I do not believe these are associated with any Google add ons as I only ever add tasks in to my Lightening Calendar. -Again, if they appear in the same file in Thunderbird 78.11 with no add ons, why do they not appear in Thunderbird 91 with no add ons? Thank you, all, for your diligent work in working out these bugs. I appreciate you very much and look forward to hearing from you soon.