The solution is to downgrade libqt5x11extras5 to libqt5x11extras5_5.4.2-2+b1_amd64 (or 385 if your system is 32bit).
You should find libqt5x11extras5_5.4.2-2+b1_amd64.deb in the /var/cache/apt/archives directory if you haven't run "apt-get clean" recently. Mine was dated Aug 9. Use "dpkg -i libqt5x11extras5_5.4.2-2+b1_amd64.deb" to install it. dpkg will notify you that it is downgrading the package. *...Bob*
