About all I could recommend at this point -- if you haven't already tried that -- is to completely remove Thunderbird and reinstall it. I would try eopkg rm --purge thunderbird
, which should not affect anything in your home folder. Then reinstall it.
If that doesn't work for you, you may need to update your repository and install again with the --replace
option.
And if it still doesn't work, I'm afraid I'm out of ideas. Good luck with it!