These steps are supposed to work, but it can be problematic: Try:

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

If you attempt that, I encourage doing a backup first, just to be safe.

Further, I encourage you to post specifics on your problems with 115, as we often find there are just a few issues to resolve. 115 has a number of settings and it may prove useful to make the changes than to revert to 102, which will never be updated again.

Thanks David, after reading that once I downgraded Thunderbird, I wouldn't be able to receive future upgrades, I've decided to see If to see if Mozilla decides to address some of the initial issues with the launch of its Thunderbird Supernova. The main reason I dislike this upgrade is because the limitations put on by Mozilla as to its adjustable window size, mainly the classic view "top & bottom" Supernova prevents the border between the Mail message indicator and the reading of the message, presently the bottom portion of the program makes it nearly impossible to read the message. This is what I need help with, is there a way to circumvent the program to allow the top portion to be raised? Presently I can't raise the Mail Message Indicator above 10 messages making a VERY small message viewing window. I know that there have been complaints about this, not sure if a solution has been found.

Rich