In http://www.fedoraforum.org/forum/showthread.php?t=273375 I found a simple solution: after deleting $HOME/.libreoffice CTRL-F works again.
See also upstream report https://bugs.freedesktop.org/show_bug.cgi?id=42251 ** Bug watch added: freedesktop.org Bugzilla #42251 https://bugs.freedesktop.org/show_bug.cgi?id=42251 -- You received this bug notification because you are a member of Ubuntu Bugs, which is subscribed to Ubuntu. https://bugs.launchpad.net/bugs/876558 Title: Libreoffice "Find" window invisible To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/libreoffice/+bug/876558/+subscriptions -- ubuntu-bugs mailing list ubuntu-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs