in settings>general in the update area, there is a button that lists your upgrade history. That should show your prior version. I STRONGLY encourage you to stay with 115 and learn a bit about it. I agree, there is a learning curve, but that will go quickly. You need to stay relatively up to date for your own protection. We are currently at 128. If you are planning to stay behind the current version, I encourage you to also backup the thunderbird exe install program so you can recreate your environment. I also suggest periodically checking to see if your backups work. we regularly see users with backups that do not work.

My previous ver list is blank. That was the first place I checked but it seems the upgrade to the last version wiped my history away. Which is why I asked if the version is listed in some INI file in my backup.

I check email maybe 2 or 3 times a week and personally do not have a desire to devote time for a learning curve for something I have no use for. But thanks for the advice Which I'm sure those that spend 2 hours a day or more in front of a computer every day of their lives will find useful.

Having upgraded through several versions you are at at point where it would be irresponsible for us to say it's OK to go back to an earlier version unless you are willing to blow away the data you have on disk - because the data have been updated and are not backwards compatible to older versions.

What in version 115 is making life most difficult for you?

I wouldn't be going back to an earlier version if someone answers my question.

1. Where is that ver number located in the copied profile so I know what ver I was running? And if I find it can I just uninstall TB and all files/profile and reinstall that version; then import my copied profile without losing 10 years of mail?

There is no version in the profile.

We can try to assist. There is no reason to lose your years of mail. Your first approach should be to try and work with 115. It is a sold, stable release. There may be a feature that is new, but if you share what troubles you, I think we can assist. I do encourage you to set Thunderbird to NOT upgrade for now until you feel comfortable with 115. That setting is at settings>general from the menu icon (three short stacked bars) in upper right. Taking the time to familiarize yourself with 115 will take much less time than your other option, that of reverting to a prior version.

Should you prefer reverting to a prior version route, we can still assist but it's crap shoot we don't recommend. Your first step would be to do a full backup of the profile. Then, to select one of the releases since 52 and 115. Possibly 102 would be a start? Going that route is a step backward and you would need to install the release, copy in the profile, see if it works to your satisfaction. Reverting to 102 might be simpler, since 102 has the ability to import profiles. This link lets you access ver 102, English, 64-bit:

   https://ftp.mozilla.org/pub/thunderbird/releases/102.15.1/win64/en-US/

Found the last version number in a file within my backed up profile. Uninstalled 115 and all TB folders. Reinstalled the version I was running then imported my backup profile. Simple and back where I was getting with all my emails. Completed over morning cup of coffee. I wasn't sure how to but now have disabled the auto upgrade feature so this never happens again.

First, I am happy for your success. But, I do encourage staying abreast. May I ask, what is now your version? Again, thanks for the news that you can now access your messages.

Not home but it's 68.(something)