Got some crash on Xenial too, fixed by doing sudo ppa-purge kubuntu-ppa/backports-landing, which downgraded the following packages to their kubuntu-ppa/backports versions:
libqt5concurrent5 libqt5core5a libqt5dbus5 libqt5gui5 libqt5network5 libqt5opengl5 libqt5printsupport5 libqt5sql5 libqt5sql5-mysql libqt5sql5-sqlite libqt5test5 libqt5widgets5 libqt5xml5
Probably some latest updates broke it.
Got some crash on Xenial too, fixed by doing sudo ppa-purge kubuntu- ppa/backports- landing, which downgraded the following packages to their kubuntu- ppa/backports versions:
libqt5concurrent5 libqt5core5a libqt5dbus5 libqt5gui5 libqt5network5 libqt5opengl5 libqt5printsupport5 libqt5sql5 libqt5sql5-mysql libqt5sql5-sqlite libqt5test5 libqt5widgets5 libqt5xml5
Probably some latest updates broke it.