Thunderbird email; can't migrate profile

Having successfully got Zorin 16.1 installed, up and running, I started the process of migrating my Thunderbird profile.
Using an article "Moving Thunderbird data to a new computer"; I gathered up the Thunderbird profile from my old OS (Z15) and onto a memory-stick. However, getting the stuff to migrate successfully to the new Thunderbird on Z16 just didn't happen; my instruction sheet is as follows:

  1. Right click your Thunderbird profile folder on your transfer device, then select Copy.
  2. Open Thunderbird (close the account set-up window if it appears)
  3. Click the Menu button then click Help--Troubleshooting information
  4. Locate the Profile Folder entry then click Open Directory
  5. Close Thunderbird
  6. From your Tbird profile fodler in the file browser, go up 2 levels
  7. Right click inside the folder then select paste.
  8. When prompted, choose to replace your current data.

After which, one would hope that re-opening Thunderbird would result in all data and settings migrating over and populating the application.
No such luck.
I noticed that although Thunderbird was already installed in my Z16.1 set-up (from Flathub), there were two other types in the Software collection. One was version 102 and the other one was version 1.91.11 (in fact the version 102 has mysteriously vanished now...)
Now I really don;'t know what I'm the moment I haven't got Tbird installed at all, I took it off in case there was a corruption.
Any ideas, please, which version is the most problem-free? and has the process of transferring a Tbird profile been changed?

If migrating from Linux, the location of your profile is in the hidden folder within /home - .thunderbird. If you can't see hidden folders, press Ctrl+ H. That is the file that contains all the data including your profile.

[I've stopped using Thunderbird now as it is too Google centric, such as not allowing me to delete the Google search engine or DuckDuckGo search engine built into it. I've migrated to Evolution.]

Thanks; yes I have the hidden folders ok. I re-installed the flatpak Thunderbird and the darned thing won't allow me to use the migration process at Steps 3 and 4---Help---Troubleshootinginfo--locate profile folder--open directory. The "open directory" button doesn't function.

I'm not too keen to use another mail system, because I have a ton of archived emails that must be kept and referred to regularly....but if it really doesn't work then I'll have a look at Evolution.

I had the exact same problem after installing Linux Mint. It turned out that my old version of TB was not the same as my new version of TB. I did this a few months ago and don't recall exactly how I got around the problem. I do remember that I did an online search and found the solution. The info you posted is the same as what I did that did NOT work. So I had to find another solution. You might try searching for a TB forum. If I can find the info I used I will post it here for you but I am going to be very busy this whole weekend so it will probably be faster for you to look for it your self. The solution is out there.

Thanks citfta, it's nice to know I'm not alone :disappointed_relieved:....yes I'm puddling along now through the search engines, there has to be an answer out there...

Finally succeeded, but using my own cunning instead of the proper instructions. Ew. Decided to install Tbird 91.11 instead of the flathub version (just couldnt make that work, no matter what).
The application already had a couple of profiles in the "about:profiles" troubleshoot section, so I decided to try and create a new profile.
I called it AUG22, but the application decided to name it something like eft65.AUG22 and then parked it in the hidden thunderbird folder and also the cache.
Then I put the original migrated AUG22 profile into the hidden thunderbird folder, deleted eft65.AUG22 and renamed my original one to match...eft65.AUG22 Ditto in the cache.
Set to default, shut the application, re-started....and it worked.
Whether or not this is the right way to do it, I don't know....all I know is, it's running and seems to be working, so I'll just give thanks for small mercies and see how it goes.