Application: umbrello (2.16.0)
KDE Platform Version: 4.14.17
Qt Version: 4.8.7
Operating System: Linux 4.4.6-201.fc22.x86_64 x86_64
Distribution: "Fedora release 22 (Twenty Two)"

-- Information about the crash:
This crash was (I think), when trying to open a new file with one already open.
I previously tried closing the open one first, but Umbrello crashed then too.
Initially it crashed just trying to open (presumably because of the file it was autoloading). When it had managed to load successfully it had complained that the view contained duplicate class names, about three of them, but I was able to rename them (accepting the simplistic ones offered) and get to a stable state.

On a separate note, having to download over 500Mb of debug symbols to file a bug report does not encourage reporting. I know symbols are required, but 500Mb?

The crash can be reproduced every time.

-- Backtrace:
Application: Umbrello UML Modeller (umbrello), signal: Segmentation fault
Using host libthread_db library "/lib64/libthread_db.so.1".
81	T_PSEUDO (SYSCALL_SYMBOL, SYSCALL_NAME, SYSCALL_NARGS)
[KCrash Handler]
#6  0x000000316de8c2b3 in __cxxabiv1::__dynamic_cast(void const*, __cxxabiv1::__class_type_info const*, __cxxabiv1::__class_type_info const*, ptrdiff_t) (src_ptr=0x60c1860, src_type=0x7d6520 <typeinfo for UMLObject>, dst_type=0x7d0d68 <typeinfo for UMLCanvasObject>, src2dst=0) at ../../../../libstdc++-v3/libsupc++/dyncast.cc:68
#7  0x00000000006e2a50 in UMLPackage::removeAssocFromConcepts(UMLAssociation*) (this=this@entry=0x2945a50, assoc=0x60a71a0) at ../../umbrello/package.cpp:113
#8  0x00000000006e3245 in UMLPackage::removeObject(UMLObject*) (this=this@entry=0x2945a50, pObject=pObject@entry=0x60a71a0) at ../../umbrello/package.cpp:198
#9  0x00000000006e339f in UMLPackage::removeAllObjects() (this=0x2945a50) at ../../umbrello/package.cpp:220
#10 0x0000000000710b4e in UMLDoc::removeAllObjects() (this=this@entry=0x277c720) at ../../umbrello/umldoc.cpp:2544
#11 0x0000000000710c1b in UMLDoc::closeDocument() (this=this@entry=0x277c720) at ../../umbrello/umldoc.cpp:345
#12 0x00000000007153a6 in UMLDoc::newDocument() (this=0x277c720) at ../../umbrello/umldoc.cpp:370
#13 0x00000000006ff696 in UMLApp::slotFileNew() (this=0x2561570) at ../../umbrello/uml.cpp:1188
#14 0x000000316e3afa50 in QMetaObject::activate(QObject*, QMetaObject const*, int, void**) (sender=sender@entry=0x2973c00, m=m@entry=0x316f4f4d80 <QAction::staticMetaObject>, local_signal_index=local_signal_index@entry=1, argv=argv@entry=0x7fff257a2ad0) at kernel/qobject.cpp:3567
#15 0x000000316e9fc9d2 in QAction::triggered(bool) (this=this@entry=0x2973c00, _t1=false) at .moc/release-shared/moc_qaction.cpp:276
#16 0x000000316e9fdd33 in QAction::activate(QAction::ActionEvent) (this=0x2973c00, event=<optimized out>) at kernel/qaction.cpp:1257
#17 0x000000316edd9b33 in QAbstractButtonPrivate::click() (this=this@entry=0x280d0f0) at widgets/qabstractbutton.cpp:530
#18 0x000000316edd9c84 in QAbstractButton::mouseReleaseEvent(QMouseEvent*) (this=0x27fe400, e=0x7fff257a3050) at widgets/qabstractbutton.cpp:1123
#19 0x000000316ee9fd0a in QToolButton::mouseReleaseEvent(QMouseEvent*) (this=<optimized out>, e=<optimized out>) at widgets/qtoolbutton.cpp:723
#20 0x000000316ea59130 in QWidget::event(QEvent*) (this=0x27fe400, event=0x7fff257a3050) at kernel/qwidget.cpp:8775
#21 0x000000316ea0293c in QApplicationPrivate::notify_helper(QObject*, QEvent*) (this=0x23f7a50, receiver=0x27fe400, e=0x7fff257a3050) at kernel/qapplication.cpp:4565
#22 0x000000316ea09956 in QApplication::notify(QObject*, QEvent*) (this=this@entry=0x7fff257a3870, receiver=receiver@entry=0x27fe400, e=e@entry=0x7fff257a3050) at kernel/qapplication.cpp:4108
#23 0x0000003172c5559a in KApplication::notify(QObject*, QEvent*) (this=0x7fff257a3870, receiver=0x27fe400, event=0x7fff257a3050) at ../../kdeui/kernel/kapplication.cpp:311
#24 0x000000316e39b8bd in QCoreApplication::notifyInternal(QObject*, QEvent*) (this=0x7fff257a3870, receiver=0x27fe400, event=0x7fff257a3050) at kernel/qcoreapplication.cpp:955
#25 0x000000316ea08f5d in QApplicationPrivate::sendMouseEvent(QWidget*, QMouseEvent*, QWidget*, QWidget*, QWidget**, QPointer<QWidget>&, bool) (receiver=receiver@entry=0x27fe400, event=event@entry=0x7fff257a3050, alienWidget=alienWidget@entry=0x27fe400, nativeWidget=nativeWidget@entry=0x2809870, buttonDown=buttonDown@entry=0x316f5359a8 <qt_button_down>, lastMouseReceiver=..., spontaneous=true) at ../../src/corelib/kernel/qcoreapplication.h:231
#26 0x000000316ea83852 in QETWidget::translateMouseEvent(_XEvent const*) (this=this@entry=0x2809870, event=event@entry=0x7fff257a33b0) at kernel/qapplication_x11.cpp:4546
#27 0x000000316ea8221d in QApplication::x11ProcessEvent(_XEvent*) (this=0x7fff257a3870, event=event@entry=0x7fff257a33b0) at kernel/qapplication_x11.cpp:3663
#28 0x000000316eaab299 in x11EventSourceDispatch(GSource*, GSourceFunc, gpointer) (s=0x2404530, callback=0x0, user_data=0x0) at kernel/qguieventdispatcher_glib.cpp:148
#29 0x0000003e71649a8a in g_main_context_dispatch () at /lib64/libglib-2.0.so.0
#30 0x0000003e71649e20 in g_main_context_iterate.isra () at /lib64/libglib-2.0.so.0
#31 0x0000003e71649ecc in g_main_context_iteration () at /lib64/libglib-2.0.so.0
#32 0x000000316e3cbe5e in QEventDispatcherGlib::processEvents(QFlags<QEventLoop::ProcessEventsFlag>) (this=0x23b9720, flags=...) at kernel/qeventdispatcher_glib.cpp:450
#33 0x000000316eaab436 in QGuiEventDispatcherGlib::processEvents(QFlags<QEventLoop::ProcessEventsFlag>) (this=<optimized out>, flags=...) at kernel/qguieventdispatcher_glib.cpp:207
#34 0x000000316e39a131 in QEventLoop::processEvents(QFlags<QEventLoop::ProcessEventsFlag>) (this=this@entry=0x7fff257a3790, flags=...) at kernel/qeventloop.cpp:149
#35 0x000000316e39a4a5 in QEventLoop::exec(QFlags<QEventLoop::ProcessEventsFlag>) (this=this@entry=0x7fff257a3790, flags=...) at kernel/qeventloop.cpp:204
#36 0x000000316e3a0039 in QCoreApplication::exec() () at kernel/qcoreapplication.cpp:1227
#37 0x000000316ea010cc in QApplication::exec() () at kernel/qapplication.cpp:3823
#38 0x000000000043dfdd in main(int, char**) (argc=<optimized out>, argv=<optimized out>) at ../../umbrello/main.cpp:123

Reported using DrKonqi