Try this: close TB, open a Run window (Winkey+R) enter thunderbird.exe -p --allow-downgrade and when Profile Manager appears, select your old profile.

Upgrading from 78 to 91 works best if a new profile is created with 91.

Thanks for the suggestion but it did not work..

re : I downgraded back to 78.0 but now it will not restore the previous session at start up.

I think you mean it would not use the profile containing all mail accounts which is not the same as session. You cannot simply go back to another version without initially starting that older version using the thunderbird.exe -p --allow-downgrade command to invoke the Profile Manager which then allows you to choose the profile and auto update various files.

re: I have tried deleting the session.json; starting in safe mode.

This would not have any effect as the problem is not to do with session or starting up without using addons.

re :Restoring previous session is essential for me. Do you mean you need Thunderbird to use the original Profile Name folder ? Are you being shown an empty new Thunderbird which is asking you to create a new mail account ?

What do you see when you do this: Menu app icon > Help > More Troubleshooting Information Under 'Application Basics' - near the bottom - 'Profiles' - click on 'about:profiles' This will open in a new tab

It will list all the profiles. It will say which profile is in use. It will say 'Default Profile: yes or no' 'Root directory' is where your Thunderbird profile is located. Below each profile will be some buttons. For the 'profile name' folder you want to use... Click on 'Set as default profile' This should update the 'profiles.ini' file, then try restarting Thunderbird to see if selects that profile.

But version 91* did alter many files and it has not been that simple to go back for a long time as it now uses a dedicated profile.

re :91+ not for me. Period. An essential add on is not compatible.

What addon are you talking about ? Some addons may need updating, some addons have a different addon available. In some cases Thunderbird has incorporated functionality, so addon is not so important. In some cases the author has not had sufficient support from thoe who use their addons, so they cannot afford to update the software. In other cases, it is simply a case of the authors do not have the time nor inclination.

Toad-Hall,

Thank you for the response but no this isn't my problem. I am well versed in moving profiles, I've been using TB since it was netscape!! My problem is that I normally have up to 12-15 tabs open. I keep "Sent", "Trash", and many "Inbox" tabs open. I keep different "inbox" tabs open with different filters applied for issues that are pending... somewhat of a diary, to-do system.... Up until recently all versions that I had been running would open all the same tabs on start up that were open when TB shut down. Even if system crashed TB would restore the tabs from previous session.

Another problem that I have with more recent versions of TB is that when you attach a .pdf file to a message you are composing TB will not open the attachment so that you can check to make sure that you have indeed attached the correct file. When you click on a .pdf file that is attached to a message you are composing you get an error message that "file can't be opened because there is no program associated with the file type". This is not the exact error message but that is the gist of it. I have my pdf reader selected as the associated file type in the settings for TB, this is not the problem... The problem with not being able to open a .pdf file that has been attached to an outgoing message has been reported numerous times through bugzilla and the team keeps saying that the bug is fixed but it is not... I use attachments all day long, at least half of all message I send have .pdf attachments so this is a big deal to me. Even though you can't open the file in the outgoing message TB does attach and send the file along with the email. When you go to your sent file you can open the .pdf file but email has already been sent.

I'm well aware of the -allow-downgrade and that is how I was able to restore my profile. I have successfully gone back to TB 78.14.0 which does open the .pdf attachments in outgoing messages but will not restore the tabs that were open from previous session.

I have been burned by TB upgrades many times over the years and wish that the team would realize that allowing users to easily go back to a previous version is critical and really the right thing to do. I have now put both FF and TB to not allow upgrade.

If you have any solution to the issue with restoring the previous open tabs on start up I would be most grateful.

I'm afraid there's little chance that TB is going to return to the days when profiles could be seamlessly interchanged with different TB versions, no matter how many users encounter problems with upgrading and downgrading. But you can bypass most of these issues by running separate TB versions on separate profiles. For example, I have TB 78, 91 and beta installed, and each version runs its own profile.

As for session restore, deleting the json file usually fixes tab retention, but it only fixes it from the point when the file is deleted. It won't restore a set of tabs that existed before the deletion. Without knowing the condition of your profile, I would recommend creating a new one, adding an account, and seeing if tab sessions are restored.

re : I have tried deleting the session.json;

That would have completely removed all session data, but it would have created a new one so it should retain tabs thereafter.

Suggest you try deleting both of these files whilst Thunderbird is not running.

• session.json
• xulstore.json

It might be another software is deleting session files. Do you have any software installed that can clean up files like CCleaner or WiseCleaner or even some Anti-Virus products can clean up files ? If yes, then you need to make Thunderbird profile files and folders exempt.

I tried deleting session.json and xulstore.json and no change....

I can't simply create new profiles. The profile that I use I have been using for for over 16 years and I need to retain all files for legal purposes.

Creating a new profile doesn't remove the current profile, or make the current one unavailable. But if saving sessions is critical to you, a new profile is probably the easiest solution, and saves a lot of time spent trying to debug the current profile. If you've been using the same profile for 16 years, it's not surprising that problems have crept in.

sfhowes, Interesting that you find it unusual that a user would need to have long standing profile with records archived for long period of time. I think that may be the issue with using TB for business. The TB team does not seem to respect that their platform is used for other than personal use. That is their prerogative, as an open source, free program I guess we really don't have a right to complain. That said, I would much rather pay for the program and have a stable platform that doesn't mandate that I update or loss functionality of the software. As I stated in an earlier post, I have been here since the beginning. I was on Netscape when Netscape had only a few users so I have a loyalty to Mozilla and I like that it is open source and free but it has gotten to the point where I can't spend the time to keep trying to tweak the software because some new update is being forced on me.

My problems with TB always are tied to an update. The fact that my profile is so large and has been ongoing for such a long period has never created any problems unless I updated.

I was stupid. I had set TB so that it did not even look for updates and I had it running perfectly for my needs. Tabs restored on startup, .pdf attachments opened when composing emails... All was good in TB world but then I stupidly updated to 91. I use Smarttempletes and they recommended updating or I would not have even considered it...

My Bad, I knew better. I have been here before. At this point I am tired of having to try and find solutions to tweak TB back to where I had it before update. Maybe it is time that I realize that I need to just go to Outlook.

Feels like leaving and old friend but at the same time maybe a better stated would be realizing that you have outgrown an old dear friend.

I didn't imply it isn't necessary to maintain records from the past. The mail folders created in any version of TB are mbox files and can be opened in any other version of TB. It is the profile folder that no longer has simple backwards compatibility. To guard against unexpected or unwanted changes in TB, I recommend installing different versions in separate folders, and running separate profiles, as described above. Create a new profile for each major, annual update of TB.

To have a separate method of archiving mail for business or personal purposes, consider an app like MailStore Home.

All cases I have come across where session is not being maintained were caused by either a corrupt session file - deleting it fixed problem OR the computer had clean up software which was deleting the session file - the fix was to make Thunderbird profile folders exempt, so those products had no access.

You have not mentioned if you are running any software that is allowed to clean up files and please note some Anti-Virus products are able to do it as well. Do you have any software installed that can clean up files like CCleaner or WiseCleaner or even some Anti-Virus products can clean up files ?