Thunderbird Update for 77 May 30th causes significant failure

The May 30th 2020 update to the Thunderbird Beta version (77) caused the loss of connectivity to a POP server, and subsequent failure with the SMTP server on my laptop connected to RCN (my ISP). Now this particular installation of the BETA Thunderbird is several years old, and now it’s broken, and essentially useless. I need help getting access to the email file folders and porting them to another computer with a reliable public (non-BETA) release version of Thunderbird. Can someone please advise? Directions for doing this only work for Version 68.

Fixed it - the reason the directions failed is because I was using a custom folder for the profile contents - When I installed Thunderbird, I gave it a specific folder on the C Drive to make backups easier. I had forgotten all about that. Problem solved. Nothing to do here.

What is the URL of the directions you were using?

https://support.mozilla.org/en-US/kb/moving-thunderbird-data-to-a-new-computer

(see entry here: https://support.mozilla.org/en-US/questions/1289428)