When I dock into the docking station with 2 monitors attached (VGA, DVI), plasmashell crashes and the system becomes unusable until multiple restarts and (every time) resetting the monitor layout via System Settings

Reproducible: Always

Steps to Reproduce:
1. use laptop undocked
2. dock laptop into docking station with 2 monitors attached

Actual Results:  
plasmashell crashes and sometimes system completely freezes

Expected Results:  
Use the two external monitors

Application: plasmashell (5.3.1)

Qt Version: 5.4.1
Operating System: Linux 4.0.4-2-ARCH x86_64
Distribution (Platform): Archlinux Packages

-- Backtrace:
Application: Plasma (plasmashell), signal: Aborted
Using host libthread_db library "/usr/lib/libthread_db.so.1".
[Current thread is 1 (Thread 0x7fa7e93317c0 (LWP 994))]

Thread 99 (Thread 0x7fa7d2691700 (LWP 1004)):
#0  0x00007fa7e2c72e8d in poll () from /usr/lib/libc.so.6
#1  0x00007fa7e7c259f2 in ?? () from /usr/lib/libxcb.so.1
#2  0x00007fa7e7c2756f in xcb_wait_for_event () from /usr/lib/libxcb.so.1
#3  0x00007fa7d3fac619 in ?? () from /usr/lib/qt/plugins/platforms/libqxcb.so
#4  0x00007fa7e335918e in ?? () from /usr/lib/libQt5Core.so.5
#5  0x00007fa7e226b354 in start_thread () from /usr/lib/libpthread.so.0
#6  0x00007fa7e2c7bbfd in clone () from /usr/lib/libc.so.6

[99 more, see attachment]

Thread 1 (Thread 0x7fa7e93317c0 (LWP 994)):
[KCrash Handler]
#5  0x00007fa7e2bc7528 in raise () from /usr/lib/libc.so.6
#6  0x00007fa7e2bc893a in abort () from /usr/lib/libc.so.6
#7  0x00007fa7e2fc5b3d in __gnu_cxx::__verbose_terminate_handler () at /build/gcc/src/gcc-5-20150519/libstdc++-v3/libsupc++/vterminate.cc:95
#8  0x00007fa7e2fc3996 in __cxxabiv1::__terminate (handler=<optimized out>) at /build/gcc/src/gcc-5-20150519/libstdc++-v3/libsupc++/eh_terminate.cc:47
#9  0x00007fa7e2fc39e1 in std::terminate () at /build/gcc/src/gcc-5-20150519/libstdc++-v3/libsupc++/eh_terminate.cc:57
#10 0x00007fa7e2fc451f in __cxxabiv1::__cxa_pure_virtual () at /build/gcc/src/gcc-5-20150519/libstdc++-v3/libsupc++/pure.cc:50
#11 0x00007fa7e3a5bdca in QPlatformScreen::physicalSize() const () from /usr/lib/libQt5Gui.so.5
#12 0x00007fa7e3a95372 in QScreen::physicalSize() const () from /usr/lib/libQt5Gui.so.5
#13 0x00007fa7e3a95429 in QScreen::physicalDotsPerInch() const () from /usr/lib/libQt5Gui.so.5
#14 0x00007fa7e6e966f3 in ?? () from /usr/lib/libQt5Quick.so.5
#15 0x00007fa7e3574ff9 in QMetaObject::activate(QObject*, int, int, void**) () from /usr/lib/libQt5Core.so.5
#16 0x00007fa7e3a72b8f in QWindow::screenChanged(QScreen*) () from /usr/lib/libQt5Gui.so.5
#17 0x00007fa7e3a73a95 in QWindowPrivate::emitScreenChangedRecursion(QScreen*) () from /usr/lib/libQt5Gui.so.5
#18 0x00007fa7e3a76ba3 in QWindowPrivate::setTopLevelScreen(QScreen*, bool) () from /usr/lib/libQt5Gui.so.5
#19 0x00007fa7e3a76d35 in QWindow::screenDestroyed(QObject*) () from /usr/lib/libQt5Gui.so.5
#20 0x00007fa7e357498a in QMetaObject::activate(QObject*, int, int, void**) () from /usr/lib/libQt5Core.so.5
#21 0x00007fa7e357572f in QObject::destroyed(QObject*) () from /usr/lib/libQt5Core.so.5
#22 0x00007fa7e357e0db in QObject::~QObject() () from /usr/lib/libQt5Core.so.5
#23 0x00007fa7e3a95239 in QScreen::~QScreen() () from /usr/lib/libQt5Gui.so.5
#24 0x00007fa7e3a5c352 in QPlatformScreen::~QPlatformScreen() () from /usr/lib/libQt5Gui.so.5
#25 0x00007fa7d3fb7b29 in ?? () from /usr/lib/qt/plugins/platforms/libqxcb.so
#26 0x00007fa7d3faab1b in ?? () from /usr/lib/qt/plugins/platforms/libqxcb.so
#27 0x00007fa7d3fab79d in ?? () from /usr/lib/qt/plugins/platforms/libqxcb.so
#28 0x00007fa7d3faca3b in ?? () from /usr/lib/qt/plugins/platforms/libqxcb.so
#29 0x00007fa7e3575d5a in QObject::event(QEvent*) () from /usr/lib/libQt5Core.so.5
#30 0x00007fa7e48b43dc in QApplicationPrivate::notify_helper(QObject*, QEvent*) () from /usr/lib/libQt5Widgets.so.5
#31 0x00007fa7e48b9820 in QApplication::notify(QObject*, QEvent*) () from /usr/lib/libQt5Widgets.so.5
#32 0x00007fa7e35449eb in QCoreApplication::notifyInternal(QObject*, QEvent*) () from /usr/lib/libQt5Core.so.5
#33 0x00007fa7e3546a2b in QCoreApplicationPrivate::sendPostedEvents(QObject*, int, QThreadData*) () from /usr/lib/libQt5Core.so.5
#34 0x00007fa7e359c9f3 in ?? () from /usr/lib/libQt5Core.so.5
#35 0x00007fa7def059fd in g_main_context_dispatch () from /usr/lib/libglib-2.0.so.0
#36 0x00007fa7def05ce0 in ?? () from /usr/lib/libglib-2.0.so.0
#37 0x00007fa7def05d8c in g_main_context_iteration () from /usr/lib/libglib-2.0.so.0
#38 0x00007fa7e359cde7 in QEventDispatcherGlib::processEvents(QFlags<QEventLoop::ProcessEventsFlag>) () from /usr/lib/libQt5Core.so.5
#39 0x00007fa7e3542482 in QEventLoop::exec(QFlags<QEventLoop::ProcessEventsFlag>) () from /usr/lib/libQt5Core.so.5
#40 0x00007fa7e3549e5c in QCoreApplication::exec() () from /usr/lib/libQt5Core.so.5
#41 0x000000000042ed66 in main ()