This is how to handle situation when Thunderbird wants to do set up from scratch after it crashed. First locate profile folder – you can do that in Thunderbird by using Help -> More troubleshooting information. Once you locate this folder looks for prefs.js and possibly prefs-1.js, prefs-2.js etc.
- Turn off Thunderbird
- Backup old
prefs.js(just in case this doesn’t work) - Find the most recent of these
prefs-*.jsfiles (most recent in sense of modification time) - Copy most recent
prefs-*.jsintoprefs.js - Start Thunderbird – if everything went well you should have all your email accounts again