I had a similar problem. Removing the file "prefs.js" in your firefox profile folder solved this. (Apparently, the configuration was broken by an extension or by updating from previous versions of firefox.)
-- Firefox address bar and "undo close tab" problem https://bugs.launchpad.net/bugs/283961 You received this bug notification because you are a member of Ubuntu Bugs, which is subscribed to Ubuntu. -- ubuntu-bugs mailing list ubuntu-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs
