Mixing desktop environments has become more and more problematic over the past few cyclesHad the bright (?) idea of using Flashback as my desktop in a Lubuntu Trusty base. Appeared to have installed OK, but choosing Flashback No Effects at logon, ended up with a desktop with solid empty black panels (see att). Alt-T into a terminal got kbd operation, but nothing changed the panel contents.
Piggybacked onto Launchpad #1245209. Don't really care whether this gets fixed or disallowed. It was just another way to provide a lighter Trusty.