Okay, I currently have two issues going on, both repercussions from transferring Thunderbird to my new computer. I'll limit this post to one issue! My transfer to the new computer was not taking; followed instructions but no profiles were loading. I thought that perhaps this was due to my initial problematic installation of T-bird decades ago, where I eventually wound up with a choose-user-profile panel that worked fine with its default setting...so I lived with that easily (see image). Thinking that this was causing the inability to load profiles on the new machine, I tested whether I could delete the never-used profiles in that panel. After just one deletion, that resulted in the "Couldn't load XPCOM" error described here: [http://example.com https://support.mozilla.org/en-US/questions/1360766] Following the instructions on that page to do a repair installation (to the letter), starting T-bird now results in the attached "profile missing or inaccessible" message. Please advise: Am I doomed? Thanks for any honest advice. (yes, my Thunderbird installation is big: seven or eight addresses, many local folders, a large history and archives.)