Plasma crashed, then restarted and dr. konqui showed up.
Before the crash i had virt-manager running, and i was transferring some files over usb with dolphin.
My distro is debian stable.

Application: Plasma (plasmashell), signal: Segmentation fault
Using host libthread_db library "/lib/x86_64-linux-gnu/libthread_db.so.1".
[Current thread is 1 (Thread 0x7f75571a4940 (LWP 2072))]

Thread 8 (Thread 0x7f74950a1700 (LWP 2914)):
#0  0x00007f7564de56ad in poll () at ../sysdeps/unix/syscall-template.S:84
#1  0x00007f75607609f6 in g_main_context_poll (priority=<optimized out>, n_fds=1, fds=0x7f7490001210, timeout=<optimized out>, context=0x7f7490002cb0) at ././glib/gmain.c:4228
#2  0x00007f75607609f6 in g_main_context_iterate (context=context@entry=0x7f7490002cb0, block=block@entry=1, dispatch=dispatch@entry=1, self=<optimized out>) at ././glib/gmain.c:3924
#3  0x00007f7560760b0c in g_main_context_iteration (context=0x7f7490002cb0, may_block=1) at ././glib/gmain.c:3990
#4  0x00007f75656fa06b in QEventDispatcherGlib::processEvents(QFlags<QEventLoop::ProcessEventsFlag>) () at /usr/lib/x86_64-linux-gnu/libQt5Core.so.5
#5  0x00007f75656a39ca in QEventLoop::exec(QFlags<QEventLoop::ProcessEventsFlag>) () at /usr/lib/x86_64-linux-gnu/libQt5Core.so.5
#6  0x00007f75654d10f3 in QThread::exec() () at /usr/lib/x86_64-linux-gnu/libQt5Core.so.5
#7  0x00007f7567d626a5 in  () at /usr/lib/x86_64-linux-gnu/libQt5Qml.so.5
#8  0x00007f75654d5da8 in  () at /usr/lib/x86_64-linux-gnu/libQt5Core.so.5
#9  0x00007f75645e8494 in start_thread (arg=0x7f74950a1700) at pthread_create.c:333
#10 0x00007f7564deeaff in clone () at ../sysdeps/unix/sysv/linux/x86_64/clone.S:97

Thread 7 (Thread 0x7f74b702f700 (LWP 2529)):
#0  0x00007f75607a60e9 in g_mutex_lock (mutex=mutex@entry=0x7f74b0000990) at ././glib/gthread-posix.c:1336
#1  0x00007f75607608f0 in g_main_context_iterate (context=context@entry=0x7f74b0000990, block=block@entry=1, dispatch=dispatch@entry=1, self=<optimized out>) at ././glib/gmain.c:3896
#2  0x00007f7560760b0c in g_main_context_iteration (context=0x7f74b0000990, may_block=1) at ././glib/gmain.c:3990
#3  0x00007f75656fa06b in QEventDispatcherGlib::processEvents(QFlags<QEventLoop::ProcessEventsFlag>) () at /usr/lib/x86_64-linux-gnu/libQt5Core.so.5
#4  0x00007f75656a39ca in QEventLoop::exec(QFlags<QEventLoop::ProcessEventsFlag>) () at /usr/lib/x86_64-linux-gnu/libQt5Core.so.5
#5  0x00007f75654d10f3 in QThread::exec() () at /usr/lib/x86_64-linux-gnu/libQt5Core.so.5
#6  0x00007f75686ec406 in  () at /usr/lib/x86_64-linux-gnu/libQt5Quick.so.5
#7  0x00007f75654d5da8 in  () at /usr/lib/x86_64-linux-gnu/libQt5Core.so.5
#8  0x00007f75645e8494 in start_thread (arg=0x7f74b702f700) at pthread_create.c:333
#9  0x00007f7564deeaff in clone () at ../sysdeps/unix/sysv/linux/x86_64/clone.S:97

Thread 6 (Thread 0x7f75461ac700 (LWP 2291)):
#0  0x00007f75645ee15f in pthread_cond_wait@@GLIBC_2.3.2 () at ../sysdeps/unix/sysv/linux/x86_64/pthread_cond_wait.S:185
#1  0x00007f756a1642c4 in  () at /usr/lib/x86_64-linux-gnu/libQt5Script.so.5
#2  0x00007f756a164309 in  () at /usr/lib/x86_64-linux-gnu/libQt5Script.so.5
#3  0x00007f75645e8494 in start_thread (arg=0x7f75461ac700) at pthread_create.c:333
#4  0x00007f7564deeaff in clone () at ../sysdeps/unix/sysv/linux/x86_64/clone.S:97

Thread 5 (Thread 0x7f7547fff700 (LWP 2230)):
#0  0x00007f75656f822e in QTimerInfoList::repairTimersIfNeeded() () at /usr/lib/x86_64-linux-gnu/libQt5Core.so.5
#1  0x00007f75656f82a3 in QTimerInfoList::timerWait(timespec&) () at /usr/lib/x86_64-linux-gnu/libQt5Core.so.5
#2  0x00007f75656f963e in  () at /usr/lib/x86_64-linux-gnu/libQt5Core.so.5
#3  0x00007f756075fedd in g_main_context_prepare (context=context@entry=0x7f753c000990, priority=priority@entry=0x7f7547ffeb20) at ././glib/gmain.c:3501
#4  0x00007f756076091b in g_main_context_iterate (context=context@entry=0x7f753c000990, block=block@entry=1, dispatch=dispatch@entry=1, self=<optimized out>) at ././glib/gmain.c:3909
#5  0x00007f7560760b0c in g_main_context_iteration (context=0x7f753c000990, may_block=1) at ././glib/gmain.c:3990
#6  0x00007f75656fa06b in QEventDispatcherGlib::processEvents(QFlags<QEventLoop::ProcessEventsFlag>) () at /usr/lib/x86_64-linux-gnu/libQt5Core.so.5
#7  0x00007f75656a39ca in QEventLoop::exec(QFlags<QEventLoop::ProcessEventsFlag>) () at /usr/lib/x86_64-linux-gnu/libQt5Core.so.5
#8  0x00007f75654d10f3 in QThread::exec() () at /usr/lib/x86_64-linux-gnu/libQt5Core.so.5
#9  0x00007f7567d626a5 in  () at /usr/lib/x86_64-linux-gnu/libQt5Qml.so.5
#10 0x00007f75654d5da8 in  () at /usr/lib/x86_64-linux-gnu/libQt5Core.so.5
#11 0x00007f75645e8494 in start_thread (arg=0x7f7547fff700) at pthread_create.c:333
#12 0x00007f7564deeaff in clone () at ../sysdeps/unix/sysv/linux/x86_64/clone.S:97

Thread 4 (Thread 0x7f754e0ba700 (LWP 2162)):
#0  0x00007f7564de56ad in poll () at ../sysdeps/unix/syscall-template.S:84
#1  0x00007f75607609f6 in g_main_context_poll (priority=<optimized out>, n_fds=1, fds=0x7f7540002e70, timeout=<optimized out>, context=0x7f7540000990) at ././glib/gmain.c:4228
#2  0x00007f75607609f6 in g_main_context_iterate (context=context@entry=0x7f7540000990, block=block@entry=1, dispatch=dispatch@entry=1, self=<optimized out>) at ././glib/gmain.c:3924
#3  0x00007f7560760b0c in g_main_context_iteration (context=0x7f7540000990, may_block=1) at ././glib/gmain.c:3990
#4  0x00007f75656fa06b in QEventDispatcherGlib::processEvents(QFlags<QEventLoop::ProcessEventsFlag>) () at /usr/lib/x86_64-linux-gnu/libQt5Core.so.5
#5  0x00007f75656a39ca in QEventLoop::exec(QFlags<QEventLoop::ProcessEventsFlag>) () at /usr/lib/x86_64-linux-gnu/libQt5Core.so.5
#6  0x00007f75654d10f3 in QThread::exec() () at /usr/lib/x86_64-linux-gnu/libQt5Core.so.5
#7  0x00007f7567d626a5 in  () at /usr/lib/x86_64-linux-gnu/libQt5Qml.so.5
#8  0x00007f75654d5da8 in  () at /usr/lib/x86_64-linux-gnu/libQt5Core.so.5
#9  0x00007f75645e8494 in start_thread (arg=0x7f754e0ba700) at pthread_create.c:333
#10 0x00007f7564deeaff in clone () at ../sysdeps/unix/sysv/linux/x86_64/clone.S:97

Thread 3 (Thread 0x7f754faff700 (LWP 2114)):
#0  0x00007f75607a6104 in g_mutex_unlock (mutex=0x7f7548000990) at ././glib/gthread-posix.c:1348
#1  0x00007f75607603f1 in g_main_context_check (context=context@entry=0x7f7548000990, max_priority=2147483647, fds=fds@entry=0x7f7548012320, n_fds=n_fds@entry=1) at ././glib/gmain.c:3760
#2  0x00007f7560760994 in g_main_context_iterate (context=context@entry=0x7f7548000990, block=block@entry=1, dispatch=dispatch@entry=1, self=<optimized out>) at ././glib/gmain.c:3926
#3  0x00007f7560760b0c in g_main_context_iteration (context=0x7f7548000990, may_block=1) at ././glib/gmain.c:3990
#4  0x00007f75656fa06b in QEventDispatcherGlib::processEvents(QFlags<QEventLoop::ProcessEventsFlag>) () at /usr/lib/x86_64-linux-gnu/libQt5Core.so.5
#5  0x00007f75656a39ca in QEventLoop::exec(QFlags<QEventLoop::ProcessEventsFlag>) () at /usr/lib/x86_64-linux-gnu/libQt5Core.so.5
#6  0x00007f75654d10f3 in QThread::exec() () at /usr/lib/x86_64-linux-gnu/libQt5Core.so.5
#7  0x00007f756a82a6d5 in  () at /usr/lib/x86_64-linux-gnu/libQt5DBus.so.5
#8  0x00007f75654d5da8 in  () at /usr/lib/x86_64-linux-gnu/libQt5Core.so.5
#9  0x00007f75645e8494 in start_thread (arg=0x7f754faff700) at pthread_create.c:333
#10 0x00007f7564deeaff in clone () at ../sysdeps/unix/sysv/linux/x86_64/clone.S:97

Thread 2 (Thread 0x7f75555ef700 (LWP 2093)):
#0  0x00007f7564de56ad in poll () at ../sysdeps/unix/syscall-template.S:84
#1  0x00007f75690bb150 in  () at /usr/lib/x86_64-linux-gnu/libxcb.so.1
#2  0x00007f75690bcee9 in xcb_wait_for_event () at /usr/lib/x86_64-linux-gnu/libxcb.so.1
#3  0x00007f7556effb69 in  () at /usr/lib/x86_64-linux-gnu/libQt5XcbQpa.so.5
#4  0x00007f75654d5da8 in  () at /usr/lib/x86_64-linux-gnu/libQt5Core.so.5
#5  0x00007f75645e8494 in start_thread (arg=0x7f75555ef700) at pthread_create.c:333
#6  0x00007f7564deeaff in clone () at ../sysdeps/unix/sysv/linux/x86_64/clone.S:97

Thread 1 (Thread 0x7f75571a4940 (LWP 2072)):
[KCrash Handler]
#6  0x00007f756566bdd0 in  () at /usr/lib/x86_64-linux-gnu/libQt5Core.so.5
#7  0x00007f756566c0b9 in  () at /usr/lib/x86_64-linux-gnu/libQt5Core.so.5
#8  0x00007f75656740a9 in  () at /usr/lib/x86_64-linux-gnu/libQt5Core.so.5
#9  0x00007f75656d15e9 in QMetaObject::activate(QObject*, int, int, void**) () at /usr/lib/x86_64-linux-gnu/libQt5Core.so.5
#10 0x00007f7565748924 in QAbstractItemModel::rowsRemoved(QModelIndex const&, int, int, QAbstractItemModel::QPrivateSignal) () at /usr/lib/x86_64-linux-gnu/libQt5Core.so.5
#11 0x00007f756564d12b in QAbstractItemModel::endRemoveRows() () at /usr/lib/x86_64-linux-gnu/libQt5Core.so.5
#12 0x00007f74b50cf408 in  () at /usr/lib/x86_64-linux-gnu/libtaskmanager.so.6
#13 0x00007f74b50d2409 in  () at /usr/lib/x86_64-linux-gnu/libtaskmanager.so.6
#14 0x00007f75656d15e9 in QMetaObject::activate(QObject*, int, int, void**) () at /usr/lib/x86_64-linux-gnu/libQt5Core.so.5
#15 0x00007f75657488b4 in QAbstractItemModel::rowsAboutToBeRemoved(QModelIndex const&, int, int, QAbstractItemModel::QPrivateSignal) () at /usr/lib/x86_64-linux-gnu/libQt5Core.so.5
#16 0x00007f756564c9d3 in QAbstractItemModel::beginRemoveRows(QModelIndex const&, int, int) () at /usr/lib/x86_64-linux-gnu/libQt5Core.so.5
#17 0x00007f75656717f5 in  () at /usr/lib/x86_64-linux-gnu/libQt5Core.so.5
#18 0x00007f75656725d6 in  () at /usr/lib/x86_64-linux-gnu/libQt5Core.so.5
#19 0x00007f7565674128 in  () at /usr/lib/x86_64-linux-gnu/libQt5Core.so.5
#20 0x00007f75656d15e9 in QMetaObject::activate(QObject*, int, int, void**) () at /usr/lib/x86_64-linux-gnu/libQt5Core.so.5
#21 0x00007f756574861c in QAbstractItemModel::dataChanged(QModelIndex const&, QModelIndex const&, QVector<int> const&) () at /usr/lib/x86_64-linux-gnu/libQt5Core.so.5
#22 0x00007f74b4e6f012 in  () at /usr/lib/x86_64-linux-gnu/libKF5ItemModels.so.5
#23 0x00007f74b4e70778 in  () at /usr/lib/x86_64-linux-gnu/libKF5ItemModels.so.5
#24 0x00007f75656d15e9 in QMetaObject::activate(QObject*, int, int, void**) () at /usr/lib/x86_64-linux-gnu/libQt5Core.so.5
#25 0x00007f756574861c in QAbstractItemModel::dataChanged(QModelIndex const&, QModelIndex const&, QVector<int> const&) () at /usr/lib/x86_64-linux-gnu/libQt5Core.so.5
#26 0x00007f7565665592 in  () at /usr/lib/x86_64-linux-gnu/libQt5Core.so.5
#27 0x00007f75656671f8 in  () at /usr/lib/x86_64-linux-gnu/libQt5Core.so.5
#28 0x00007f75656d15e9 in QMetaObject::activate(QObject*, int, int, void**) () at /usr/lib/x86_64-linux-gnu/libQt5Core.so.5
#29 0x00007f756574861c in QAbstractItemModel::dataChanged(QModelIndex const&, QModelIndex const&, QVector<int> const&) () at /usr/lib/x86_64-linux-gnu/libQt5Core.so.5
#30 0x00007f74b50e8727 in TaskManager::XWindowTasksModel::Private::dataChanged(unsigned long long, QVector<int> const&) () at /usr/lib/x86_64-linux-gnu/libtaskmanager.so.6
#31 0x00007f74b50eac22 in TaskManager::XWindowTasksModel::Private::windowChanged(unsigned long long, QFlags<NET::Property>, QFlags<NET::Property2>) () at /usr/lib/x86_64-linux-gnu/libtaskmanager.so.6
#32 0x00007f74b50eaceb in  () at /usr/lib/x86_64-linux-gnu/libtaskmanager.so.6
#33 0x00007f75656d195e in QMetaObject::activate(QObject*, int, int, void**) () at /usr/lib/x86_64-linux-gnu/libQt5Core.so.5
#34 0x00007f75678853c8 in KWindowSystem::windowChanged(unsigned long long, QFlags<NET::Property>, QFlags<NET::Property2>) () at /usr/lib/x86_64-linux-gnu/libKF5WindowSystem.so.5
#35 0x00007f754e4d931e in  () at /usr/lib/x86_64-linux-gnu/qt5/plugins/kf5/org.kde.kwindowsystem.platforms/KF5WindowSystemX11Plugin.so
#36 0x00007f75656a2b0f in QAbstractEventDispatcher::filterNativeEvent(QByteArray const&, void*, long*) () at /usr/lib/x86_64-linux-gnu/libQt5Core.so.5
#37 0x00007f7556f01334 in QXcbConnection::handleXcbEvent(xcb_generic_event_t*) () at /usr/lib/x86_64-linux-gnu/libQt5XcbQpa.so.5
#38 0x00007f7556f02015 in QXcbConnection::processXcbEvents() () at /usr/lib/x86_64-linux-gnu/libQt5XcbQpa.so.5
#39 0x00007f75656d2499 in QObject::event(QEvent*) () at /usr/lib/x86_64-linux-gnu/libQt5Core.so.5
#40 0x00007f7565f88b8c in QApplicationPrivate::notify_helper(QObject*, QEvent*) () at /usr/lib/x86_64-linux-gnu/libQt5Widgets.so.5
#41 0x00007f7565f90341 in QApplication::notify(QObject*, QEvent*) () at /usr/lib/x86_64-linux-gnu/libQt5Widgets.so.5
#42 0x00007f75656a59e0 in QCoreApplication::notifyInternal2(QObject*, QEvent*) () at /usr/lib/x86_64-linux-gnu/libQt5Core.so.5
#43 0x00007f75656a816d in QCoreApplicationPrivate::sendPostedEvents(QObject*, int, QThreadData*) () at /usr/lib/x86_64-linux-gnu/libQt5Core.so.5
#44 0x00007f75656f9c43 in  () at /usr/lib/x86_64-linux-gnu/libQt5Core.so.5
#45 0x00007f75607607f7 in g_main_dispatch (context=0x7f75500016f0) at ././glib/gmain.c:3203
#46 0x00007f75607607f7 in g_main_context_dispatch (context=context@entry=0x7f75500016f0) at ././glib/gmain.c:3856
#47 0x00007f7560760a60 in g_main_context_iterate (context=context@entry=0x7f75500016f0, block=block@entry=1, dispatch=dispatch@entry=1, self=<optimized out>) at ././glib/gmain.c:3929
#48 0x00007f7560760b0c in g_main_context_iteration (context=0x7f75500016f0, may_block=1) at ././glib/gmain.c:3990
#49 0x00007f75656fa04f in QEventDispatcherGlib::processEvents(QFlags<QEventLoop::ProcessEventsFlag>) () at /usr/lib/x86_64-linux-gnu/libQt5Core.so.5
#50 0x00007f75656a39ca in QEventLoop::exec(QFlags<QEventLoop::ProcessEventsFlag>) () at /usr/lib/x86_64-linux-gnu/libQt5Core.so.5
#51 0x00007f75656ac13c in QCoreApplication::exec() () at /usr/lib/x86_64-linux-gnu/libQt5Core.so.5
#52 0x000055e5626a806f in  ()
#53 0x00007f7564d262b1 in __libc_start_main (main=0x55e5626a7510, argc=2, argv=0x7ffd0b4b98b8, init=<optimized out>, fini=<optimized out>, rtld_fini=<optimized out>, stack_end=0x7ffd0b4b98a8) at ../csu/libc-start.c:291
#54 0x000055e5626a83ea in _start ()