Please try the information at the following link to see if this allows you to choose the default profile.

• https://thunderbirdtweaks.blogspot.com/2019/09/i-lost-my-profilemail-on-update-to.html

Since I was already having trouble, I upgraded from 32 to 64 bit, same 68.8 version. In "about profile" I have default which I think is from the 64 bit install and default-release which is from when I deleted profiles earlier and created a new one. I copied my old profile into default-release and that is the current default. I have others in that directory not listed which are backups of my old default from attempting this before. This is where things get fuzzy. I create a new profile with the name default user and I assume the "choose folder" step is to pick my old profile which I renamed blah.old. I do that which sets it as a the default profile. I click on launch profile in new browser with the same results. I have 4 profiles in the profile directory, three identical to my old profile and one empty one.

It finds the address book so maybe it's just the email accounts it can't find.

if the address book is there then your in your profile. Exactly what is happening. Your explanation so far involves a lot of copying and assumptions. So I am having difficulty working out exactly what you have done since you were prompted to create a new profile.

Well the first thing I did was find out where my profile should be and hoping I had a backup. It was still there with my email account dirs in the mail dir. So then I thought it was something about the upgrade and there would be a fix to upgrade the profile. All I found were links like the one posted above that mostly said to create a new profile and copy the contents of my old one to it. Then I thought to check the address book and saved passwords which were there with my profiles but not with newly added profiles. So then I gathered it was actually seeing the profile, just not the email accounts. Where does it pick up that information? I'm thinking there is an accounts.ini like there is a profile.ini that got clobbered. I'm reasonably assured all me emails are still there. I loaded several of the files in the email dirs and it looked legit. Long story short, all I've done so far is create new profiles and copy old profiles to them or create new profiles and point them to old directories. The only setting I changed was from the profile manager. I unselected the use selected profile without asking so I see all the active profiles on startup.

I wrote the link above and it does not say create a new profile. It says locate your old profile and tell Thunderbird to use it. If it is damaged them you think about other things.

There is a profile.ini that tells Thunderbird where to locate your registered profiles (you can have many) each profile contains a prefs.js file that contains everything relevant to your profile, from account details to your address books and add-ons.

When you go to the menu and select options > Account Settings are your accounts shown?

Something else to try. As you now seem to have the correct profile set as default, hence why you can see address books, this current problem might be a known issue with global search database file. So it is worth trying to rule it out.

Exit Thunderbird and access the 'profile name' folder.

Delete this file: global-messages-db.sqlite

Restart Thunderbird.

I wrote the link above and it does not say create a new profile. It says locate your old profile and tell Thunderbird to use it. If it is damaged them you think about other things. There is a profile.ini that tells Thunderbird where to locate your registered profiles (you can have many) each profile contains a prefs.js file that contains everything relevant to your profile, from account details to your address books and add-ons. When you go to the menu and select options > Account Settings are your accounts shown?

You may be on to something. I have 4 prefs.js files in my profile. I will try renaming them from the latest till the original and see if that is what is wrong. BTW, I started by reading other threads on the subject and following other links which had me create a new profile and copy the old one to it before I opened my own thread.

Edit: That did it. thanks. Since prefs.js and prefs-2.js were created after the problem, I renamed them all and copied jprefs-1.js to jprefs.js, started up t'bird and it worked.