OK, now I'm truly embarrassed. I must have clicked the divider between the folder pane and the message pane at some point, hiding the folder pane. I couldn't find any information about how to display the folder pane, but eventually I found information about how to hide the folders. So I clicked the left side of the message pane and the folder pane came back. So it wasn't a bug after all, just a feature the user didn't know about!
-- Thunderbird lost folders https://bugs.launchpad.net/bugs/154420 You received this bug notification because you are a member of Ubuntu Bugs, which is the bug contact for Ubuntu. -- ubuntu-bugs mailing list ubuntu-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs
