This step often works to revert to prior release without starting from scratch, but no guarantees:

Try:

   Exit Thunderbird if running.
   click windows key and 'r' key
   Enter: thunderbird.exe -P --allow-downgrade
   click on 'OK' 

But I don't recommend it. You will be stuck in 102, while 115 continues to improve with each release.

I did not try this yet, I have a fresh install on a new drive so I didn't know whether this would be a solution.

For your security, please do not use unofficial sources!

This looks to be the last release of Thunderbird in the 102 series. This is U.S. English. If you prefer a different locale, click the .. link above the file names to show the full list of locales/languages.

https://archive.mozilla.org/pub/thunderbird/releases/102.9.1/win64/en-US/

See next reply for the latest.

This looks to be the last release of Thunderbird in the 102 series.

No, the latest version in the 102 series is 102.13.1, and it's still supported. https://ftp.mozilla.org/pub/thunderbird/releases/102.13.1/

Sorry about that! I forget that 102.10 sorts after 102.1 instead of after 102.9 on that list.

This step often works to revert to prior release without starting from scratch, but no guarantees: Try: Exit Thunderbird if running. click windows key and 'r' key Enter: thunderbird.exe -P --allow-downgrade click on 'OK' But I don't recommend it. You will be stuck in 102, while 115 continues to improve with each release.

I don't like 115.1.0 and want to roll back to 102.13.0, which I was using before I upgraded. I tried the above and it opened version 78... That's not what I want. So I tried running the 102.13.0 setup executable ...102.13.0.exe, which I still have in my downloads folder. That seemed to install OK, but it refuses to run unless I use -P --allow-downgrade, and then I get version 78... again. It's complaining that 115.1.0 may have changed my profiles somehow to make them incompatible. What's going on here?

I think TB needs a more robust rollback sequence so those of us who need to keep working can do so without having to take time out to get used to some shiny new stuff we might not like every time somebody dumps it on us.

Thank you for your replies. I did downgrade. I wish that there were a way to get the visual appearance of the 102.x in the 115.x

I still don't know how to downgrade back to what I was using before (102), which worked fine with my previous profile setup before 115 apparently modified it. I definitely don't want to go all the way back to 78. Maybe the trouble has to do with my custom file locations. I don't expect anyone to debug all the arcane customizing users do, especially with software that has accreted far beyond its original ideas, but I do expect to be able to keep working when I don't have time to upgrade my head because it's suddenly incompatible with my computer, which is why I think TB needs to back things up before it scrambles the files in an update, and make it easy for users to go back to what worked before.