What add-ons were you using? I could check to see what's available or whether a newer version has been created.

re: going back to a previous version. Ever since version 68 came out there has been a dedicated profile per version. https://support.mozilla.org/en-US/kb/dedicated-profile-thunderbird-installation

Thunderbird 78 made even more changes eg: the address books used to use the format .mab and now those files have been reformatted as sqlite files.

There is a method to go back but you would need to follow very specific instructions.

So using version 78 do the following. Need to set updates to ask, change the address book, uninstall, then download old and reinstall, but do not auto start. Then use command line to force a backwards compatibily allowance.

• Menu app icon > Options > General
• Scroll down to 'Updates' section
• select 'check for updates, but let me choose whether to install them'

To add also those email addresses back follow below steps: In Thunderbird

• Help >Troubleshooting Information.

Under Application Basics section about 8 down in list see 'Profile Folder'.

• Click on 'Open Folder'

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

• Exit Thunderbird

In the profile name folder - you will find the old address book files with extension .mab.bak - those files (abook and history) you need to:

• -rename them to .mab (so remove the .bak part) eg: 'abook.mab.bak' becomes 'abook.mab'
• -rename abook.sqlite and history.sqlite by adding .bak to the name. eg: abook.sqlite.bak
• Do same for any other address books you created.

Now uninstall Thunderbird program. You could just delete the Mozilla Thunderbird folder from here:

• C:\ Program Files (x86)\Mozilla Thunderbird
• then empty the computer 'Recycle Bin'

Then get download from here:

• http://ftp.mozilla.org/pub/thunderbird/releases/68.12.1/
• choose appropriate OS, then choose language, then download the Thunderbird Setup 68.12.1.exe file

Run the downloaded .exe file to install. On the last step of the installation do NOT select to start TB.

You will need to run a command to allow you to downgrade.

Windows OS:

• In search type : Run
• Select the 'Run' app
• Type: thunderbird.exe -P --allow-downgrade

note there is a space before and after -P

• click on OK

Profile Manager starts select the desired profile name click on 'Start Thunderbird'.

Hi Toad. Thanks a lot for Your support. Sure, i tried to check if there are any upgrades plugins there, but except of one(unimportant) no progress. Authors do rebuilding their soft slowly, so you have to wait a lot (and sometime to pay for it) (if you are the lucky and plugin will not cancelled definitively) I'm just studying your procedure... I already set updates to ask, uninstalled NEW and installed OLD (68.12.1). But i did not the magic around address book and started TB68 (fail) Q1: Should i uninstall 68 and install 7x to complete magic with address book? I guess that not, i found those *.mab.bak and also sqlite files ...so i can do rename them. Do You agree? Q2:I already started TB68... is still OK to rename those MAB and SQLITE files and run command line ? I ask to be sure ...and not to damage it even more...

And what do You think about request for checking plugins etc BEFORE install..?

Hi Toad-Hall.

I wrote a long reply ...but .. All those moments will be lost in time, like tears in rain. So again.. Plugins: I tested if there are some upgraded, but except of one all remained disabled. As common expectation could be seen that authors will need some more time to rebuild their plugins (and eventually you have to pay for it in some cases). (If you are lucky one and your beloved plugin remain unsupported). I have some questions. I already did before: Set actualization to ask, uninstalled, installed 68.12.1 and run. So i skipped magic with address book. Q1:I found those mab.bak and sqlite files. Can i rename them in this state without need of installing and uninstalling TB7x again? Q2:I already started downgraded TB68...did it harmed ? Or i can proceed with command line? I am asking to be sure and do not damage something more.

To my 2nd problem: How do You see it with request to check compatibility BEFORE installing new version? With regards, Martin

I, too, am irritated by the changes to 78 - there are addons that I really like to use and the authors are so fed up with TB moving the goalposts that they have thrown in the towel. I don't blame them.

The other day, I spent a few hours rebuilding my v68 TB profile due to corruption, and had just got it back and running to my liking on v68. Now I find that it has automatically updated to v78 (foolishly, I wasn't expecting that as I thought it wasn't doing major updates automatically). Then I reinstalled v68 but had the newer version error message. I didn't know about the allow downgrade option (it would be helpful to mention it in the error message box). So I just spent another happy hour downgrading manually - fortunately I'm clued up enough to know what to copy over from the updated profile and all seems to be working ok.

(the addons I rely on are account colours and tab toolbar - I can't understand that TB doesn't allow colour coding of accounts - If I didn't rely so heavily on tags, I'd be moving to another client such as Airmail to harmonise with my mobile devices).

The frequently-updated list of 78 add-ons is here:

https://cleidigh.github.io/ThunderKdB/xall/extension-list-tbmx.html

Account Colors will probably not be updated, but BorderColors D is similar.

Perhaps you meant Tag Toolbar? There is a version for 78.

Thanks, but Border Colours states that it for the new message window (ie compose) and not for the main message list, the latter is what I want. The Tag Toolbar/Popup version for 78 is very different and I found it nothing like as convenient.

Irrespectively of fact that it maybe exists somewhere in this universe a plugin which tends to be similar to currently used...i definitely do not want to spend rest of my time by searching for it. I would prefer to use my beloved precious plugin even for price of unactual TB. Yes, such people exists. At least for a while until someone adapts his plugin. It can last a months. And therefore i would like to have fair information: When you allow me to do THIS, you have to count that it will break THAT. BTW: Tab toolbar is for me a major reason why NOT to upgrade to TB7x...

Funny, my first attempt to send a reply here (was not available for at least 15 min and therefore i wrote new) appeared today... I followed Toad suggested procedure (modified) and been successful. At first moment i was stressed, that TB had no plugins, but then i selected in plugin actualization window 'search for new versions' and my beloved precious rin..plugins appeared (after restart). Thanks a lot for help, Toad. BTW to auditorium: my crucial plugins are Send Later https://blog.kamens.us/send-later/ and QuickFolders https://quickfolders.org/index.html They are already working on new version, but you know...

Additionally: Do You think that 1)my case is so rare that it is not necessary to prepare and publish this for me clear downgrade procedure for public? 2)or am i such incompetent person , who is not able to find this procedure in FAQ? Have a nice day :) Martin

re :The Tag Toolbar It was forced to change because the ability to add a new toolbar API was removed. I did create a bug report but the people in charge were not sympathetic about the request. https://bugzilla.mozilla.org/show_bug.cgi?id=1658559