Hello ICH777,
Thanks a lot for your so quick answer.
That's actually a mistake, and I changed it, but that's not THE mistake. I'm quite sure I'm making another mistake somewhere or missing something when installing it or after installing it.
In fact, when I launch the container, the install starts but stops almost immediately, and i'm left with this file in my thunderbird folder:
When I change the en-US for fr, it starts to download the "Thunderbird--fr.tar.bz2" archive, but it also stops at 0 octet and the journal still says "something went wrong..."
I would understand if you don't have time for that, but I think I'm missing something when installing the container.
Thank you for your help!