Further to this, I have discovered that if I write a new email, and start typing in the address, the set of possibles does appear - so obviously the address book content is there, yet the address book appears empty?? And in creating a new email, the Send button is activated, not greyed out. But it still doesn't actually send.

just check the file properties are not set to read only. I have only seen it once since the last release, but if it happened once.

Thanks for responding. But neither abook.sqlite or history.sqlite are marked read-only. Really pee'd off with the situation and seriously thinking of not persevering with Thunderbird. However, I had wondered if I could get round at least part of the problem. In my backed up Profile I have a lot of useful saved message folders. As it is, with the dead address book, I can read those old emails but do nothing with them. So I set up Thunderbird again with a fresh new profile - and of course an empty address book - with just one email address specified, and with that working OK, I grafted in the 'Mail' sub-folder from the backed-up Profile into the new Profile. I thought that might give me a working Thunderbird with all those old mail folders included and usable - but the imported folders didn't show. If this a feasible idea and if so, are there other Profile sub-folders I'd need to include too? Any advice much appreciated!

Did you reinsatll the same version of Thunderbird which you had last used on the baclup profile? If not sure - no etc.. re :In my backed up Profile What version of Thunderbird was last used on that backup when it was the profile in use? Info would be found in the backup copy profile name folder - open the 'compatibility.ini' file using a text editor like Notepad.

It would say something like this: [Compatibility] LastVersion=78.14.0_20210901192859/20210901192859 LastOSABI=WINNT_x86-msvc LastPlatformDir=C:\Program Files (x86)\Mozilla Thunderbird LastAppDir=C:\Program Files (x86)\Mozilla Thunderbird

If the version number is different from the one you recently installed....... Exit Thunderbird. uninstall current version. Replace current profile 'Thunderbird' folder with the backup Thunderbird folder. download and install same version last used on backup.

Old installations found here: http://ftp.mozilla.org/pub/thunderbird/releases/

So if 78.14.0 then http://ftp.mozilla.org/pub/thunderbird/releases/78.14.0/ Select OS, then select language, then download the exe file

After starting if all ok, try to update.

Hey that's a really neat idea, well explained too, thank you. But.......I just did all that, exactly as you describe, and still the address book appears as blank and cannot be updated. Really weird. The data is obviously still there - if I use the address search function, it will say 'so many matches found down' in the bottom left. If I try and create a new email, and start typing in the addressee name in the 'To' box, the addresses pop up. But if I continue and try and send that message, nothing happens. And if I try to reply to an old message, the 'send' box is greyed out. Gotta be a way round this surely.....

If you had completely removed current Thunderbird program and Thunderbird profile Then reinstalled both the Thunderbird profile backup followed by installed the last good Thunderbird version used by the backup, and the Address Book is still not correct - that would imply you created a backup after the Address Book was not working, is that correct?

Q: What version did the backup 'compatibility.ini' file say the backed up copy had been using at the time of backup? Please confirm you are still using that version at the moment.

Check to see if the global database or another session type file in interfering and post images that show what information is in the 'pref.js' file.

1. Exit Thunderbird.

2. Access Profile

3. locate and delete this files - do not worry they get created again when you start Thunderbird later on:

  * global-messages-db.sqlite
  * panacea.dat
  * session.json
  * xulstore.json

4. What are the KB sizes of the 'abook.sqlite' and 'history.sqlite' files?

5. Open the 'prefs.js' file using a text editor eg: Notepad

  (i)    scroll down until you see lines that start with: user_pref("ldap_2.servers.......)
  (ii)   make sure window is long enough and wide enough to display all the data.
  (iii)  use 'Alt' + 'Prt Scr' keys to capture image on clipboard
  (iv)  Open a simple image program like 'Paint'
  (v)   Use 'Ctrl'+'V' to paste into Paint
  (vi)  Save file as a jpg  

6. Start Thunderbird.

In this forum, when posting information, use the 'Add Images' - Browse button - locate saved jpg image, select image, click on 'Open' to upload. I need to check the ldap data in the 'prefs.js' file is correct.

Thanks again for taking all this trouble. Yes the addr book was OK at time of backup as far as I know Level is 78.14.0, still in use. I deleted those files. abook.sqlite is 320K, history.sqlite is 2176K. But.... When I tried to open prefs.js I got an immedaite error, see attached pic.

Does that tell you anything?

re :When I tried to open prefs.js

Did you right click on 'prefs.js' file and select 'Open with' and choose 'Notepad ?

If you had double clicked on the file to open it then you would have got that error message.

OOps yes you're right, sorry. Done it now, see attached pic.

Prefs.js - The info is using the correct dirtype.

Is autocomplete enabled in: Menu app icon > Options > Composition Scroll to 'Addressing' section when addressing, look for matching..... select 'Local Address Books'

Yes, it is.

OK, I'm still tinkering with the system and have got some progress, in that I have recovered all my populated email content by copying the backups of the MAIL and IMAP folders into the profile of a fresh TB setup. But of course the address book, while working, is new and empty. Is there any way, please, of opening the ABOOK and HISTORY sqlite files in my backed-up profile such that I can easily get the contents listed in plain English, so that I can get it all imported into my new, working but empty address book? I've looked at the 2 files with Notepad and it's obvious that all the addresses are there.

It seems difficult to determine whether something is wrong with the address book sqlite files or whether some other setting in the old profile is causing a conflict -

re : into the profile of a fresh TB setup.

As you have created a new profile and just migrated over only the emails, I would try: Exit Thunderbird In new profile: Rename 'abook.sqlite' to says 'abook.sqlite.bak' Rename 'history.sqlite' to says 'history.sqlite.bak'

Then get a copy of the backup 'abook.sqlite' and 'history.sqlite' and paste them into the new 'profile name' folder.

Start thunderbird on that new profile.

REport back on results.

Hey, thanks again for helping out. I was SURE I'd tried this several days ago and it didn't work. But anyway I thought I'd do it again so you could see screen shots of the 'good' and 'bad' libraries. To my utter astonishment, IT WORKED! Looks like we are there. Thank you so much @Toad-Hall for persevering with this, I'm very grateful.

Hey, thanks again for helping out. I was SURE I'd tried this several days ago and it didn't work. But anyway I thought I'd do it again so you could see screen shots of the 'good' and 'bad' libraries. To my utter astonishment, IT WORKED in that I can now see all the contacts, and I can add contacts. The send button now highlights when formatting a message to send. BUT it won't send, it just hangs. So nearly there............any ideas?