Шаги воспроизведения: 
1. Открыть freecad;
2. Создать/открыть любой проект;
3. Переключить верстак на FEM;
4. Кликнуть кнопку Opens the FreeCAD material editor

Фактический результат: Аварийное завершение работы FreeCAD.
Ожидаемый результат: Открытие окна редактора материалов. 

Ниже приведен вывод терминала: 
Program received signal SIGSEGV, Segmentation fault.
#0  /lib64/libc.so.6(+0x37770) [0x7f9153143770]
#1  /lib64/libexpat.so.1(XML_SetHashSalt+0x1b) [0x7f914d70c35b]
#2  /usr/lib64/python2.7/lib-dynload/pyexpat.so(+0x382c) [0x7f9130e1282c]
#3  /usr/lib64/libpython2.7.so.1.0(PyEval_EvalFrameEx+0x8175) [0x7f915418c325]
#4  /usr/lib64/libpython2.7.so.1.0(PyEval_EvalCodeEx+0x712) [0x7f915418dee2]
#5  /usr/lib64/libpython2.7.so.1.0(+0x7966e) [0x7f915410666e]
#6  /usr/lib64/libpython2.7.so.1.0(PyObject_Call+0x53) [0x7f91540db883]
#7  /usr/lib64/libpython2.7.so.1.0(+0x5d0ec) [0x7f91540ea0ec]
#8  /usr/lib64/libpython2.7.so.1.0(PyObject_Call+0x53) [0x7f91540db883]
#9  /usr/lib64/libpython2.7.so.1.0(+0xb5ac2) [0x7f9154142ac2]
#10  /usr/lib64/libpython2.7.so.1.0(+0xb1c3a) [0x7f915413ec3a]
#11  /usr/lib64/libpython2.7.so.1.0(PyObject_Call+0x53) [0x7f91540db883]
#12  /usr/lib64/libpython2.7.so.1.0(PyEval_EvalFrameEx+0x4d99) [0x7f9154188f49]
#13  /usr/lib64/libpython2.7.so.1.0(PyEval_EvalCodeEx+0x712) [0x7f915418dee2]
#14  /usr/lib64/libpython2.7.so.1.0(PyEval_EvalFrameEx+0x6ea3) [0x7f915418b053]
#15  /usr/lib64/libpython2.7.so.1.0(PyEval_EvalCodeEx+0x712) [0x7f915418dee2]
#16  /usr/lib64/libpython2.7.so.1.0(PyEval_EvalFrameEx+0x6ea3) [0x7f915418b053]
#17  /usr/lib64/libpython2.7.so.1.0(PyEval_EvalCodeEx+0x712) [0x7f915418dee2]
#18  /usr/lib64/libpython2.7.so.1.0(PyEval_EvalFrameEx+0x6ea3) [0x7f915418b053]
#19  /usr/lib64/libpython2.7.so.1.0(PyEval_EvalCodeEx+0x712) [0x7f915418dee2]
#20  /usr/lib64/libpython2.7.so.1.0(PyEval_EvalFrameEx+0x6ea3) [0x7f915418b053]
#21  /usr/lib64/libpython2.7.so.1.0(PyEval_EvalCodeEx+0x712) [0x7f915418dee2]
#22  /usr/lib64/libpython2.7.so.1.0(+0x7959c) [0x7f915410659c]
#23  /usr/lib64/libpython2.7.so.1.0(PyObject_Call+0x53) [0x7f91540db883]
#24  /usr/lib64/libpython2.7.so.1.0(+0x5d0ec) [0x7f91540ea0ec]
#25  /usr/lib64/libpython2.7.so.1.0(PyObject_Call+0x53) [0x7f91540db883]
#26  /usr/lib64/libpython2.7.so.1.0(PyEval_CallObjectWithKeywords+0x43) [0x7f9154183c63]
#27  /usr/lib64/libpython2.7.so.1.0(PyInstance_New+0x66) [0x7f91540ef6c6]
#28  /usr/lib64/libpython2.7.so.1.0(PyObject_Call+0x53) [0x7f91540db883]
#29  /usr/lib64/libpython2.7.so.1.0(PyEval_EvalFrameEx+0x4d99) [0x7f9154188f49]
#30  /usr/lib64/libpython2.7.so.1.0(PyEval_EvalCodeEx+0x712) [0x7f915418dee2]
#31  /usr/lib64/libpython2.7.so.1.0(PyEval_EvalFrameEx+0x6ea3) [0x7f915418b053]
#32  /usr/lib64/libpython2.7.so.1.0(PyEval_EvalCodeEx+0x712) [0x7f915418dee2]
#33  /usr/lib64/libpython2.7.so.1.0(PyEval_EvalCode+0x19) [0x7f915418e179]
#34  /usr/lib64/libpython2.7.so.1.0(PyRun_StringFlags+0x76) [0x7f91541b3176]
#35  0x7f9154b9f971 in Gui::Application::sDoCommand(_object*, _object*) from /usr/lib64/freecad/lib/libFreeCADGui.so+0x91
#36  /usr/lib64/libpython2.7.so.1.0(PyEval_EvalFrameEx+0x8175) [0x7f915418c325]
#37  /usr/lib64/libpython2.7.so.1.0(PyEval_EvalCodeEx+0x712) [0x7f915418dee2]
#38  /usr/lib64/libpython2.7.so.1.0(+0x7959c) [0x7f915410659c]
#39  /usr/lib64/libpython2.7.so.1.0(PyObject_Call+0x53) [0x7f91540db883]
#40  /usr/lib64/libpython2.7.so.1.0(+0x5d0ec) [0x7f91540ea0ec]
#41  /usr/lib64/libpython2.7.so.1.0(PyObject_Call+0x53) [0x7f91540db883]
#42  /usr/lib64/libpython2.7.so.1.0(PyEval_CallObjectWithKeywords+0x43) [0x7f9154183c63]
#43  /usr/lib64/freecad/lib/libFreeCADBase.so(PP_Run_Method+0xe7) [0x7f915440f247]
#44  0x7f91543a2649 in Base::InterpreterSingleton::runMethodVoid(_object*, char const*) from /usr/lib64/freecad/lib/libFreeCADBase.so+0x29
#45  0x7f9154c17478 in Gui::PythonCommand::activated(int) from /usr/lib64/freecad/lib/libFreeCADGui.so+0x88
#46  0x7f9154c1a494 in Gui::Command::invoke(int) from /usr/lib64/freecad/lib/libFreeCADGui.so+0x54
#47  0x7f91537974db in QMetaObject::activate(QObject*, int, int, void**) from /usr/lib64/libQt5Core.so.5+0x79b
#48  0x7f9153b84002 in QAction::triggered(bool) from /usr/lib64/libQt5Widgets.so.5+0x42
#49  0x7f9153b86610 in QAction::activate(QAction::ActionEvent) from /usr/lib64/libQt5Widgets.so.5+0xf0
#50  /usr/lib64/libQt5Widgets.so.5(+0x24bb5d) [0x7f9153c74b5d]
#51  0x7f9153c74d95 in QAbstractButton::mouseReleaseEvent(QMouseEvent*) from /usr/lib64/libQt5Widgets.so.5+0xe5
#52  0x7f9153d5f1ca in QToolButton::mouseReleaseEvent(QMouseEvent*) from /usr/lib64/libQt5Widgets.so.5+0xa
#53  0x7f9153bc9c68 in QWidget::event(QEvent*) from /usr/lib64/libQt5Widgets.so.5+0x1d8
#54  0x7f9153d5f273 in QToolButton::event(QEvent*) from /usr/lib64/libQt5Widgets.so.5+0x33
#55  0x7f9153b8a571 in QApplicationPrivate::notify_helper(QObject*, QEvent*) from /usr/lib64/libQt5Widgets.so.5+0x81
#56  0x7f9153b91c77 in QApplication::notify(QObject*, QEvent*) from /usr/lib64/libQt5Widgets.so.5+0x457
#57  0x7f9154bec008 in Gui::GUIApplication::notify(QObject*, QEvent*) from /usr/lib64/freecad/lib/libFreeCADGui.so+0x88
#58  0x7f915376d879 in QCoreApplication::notifyInternal2(QObject*, QEvent*) from /usr/lib64/libQt5Core.so.5+0x179
#59  0x7f9153b90fbf in QApplicationPrivate::sendMouseEvent(QWidget*, QMouseEvent*, QWidget*, QWidget*, QWidget**, QPointer<QWidget>&, bool, bool) from /usr/lib64/libQt5Widgets.so.5+0x1af
#60  /usr/lib64/libQt5Widgets.so.5(+0x1bb3fb) [0x7f9153be43fb]
#61  /usr/lib64/libQt5Widgets.so.5(+0x1be3a5) [0x7f9153be73a5]
#62  0x7f9153b8a571 in QApplicationPrivate::notify_helper(QObject*, QEvent*) from /usr/lib64/libQt5Widgets.so.5+0x81
#63  0x7f9153b91a30 in QApplication::notify(QObject*, QEvent*) from /usr/lib64/libQt5Widgets.so.5+0x210
#64  0x7f9154bec008 in Gui::GUIApplication::notify(QObject*, QEvent*) from /usr/lib64/freecad/lib/libFreeCADGui.so+0x88
#65  0x7f915376d879 in QCoreApplication::notifyInternal2(QObject*, QEvent*) from /usr/lib64/libQt5Core.so.5+0x179
#66  0x7f915174371b in QGuiApplicationPrivate::processMouseEvent(QWindowSystemInterfacePrivate::MouseEvent*) from /usr/lib64/libQt5Gui.so.5+0x70b
#67  0x7f9151744ad5 in QGuiApplicationPrivate::processWindowSystemEvent(QWindowSystemInterfacePrivate::WindowSystemEvent*) from /usr/lib64/libQt5Gui.so.5+0x135
#68  0x7f9151720c4b in QWindowSystemInterface::sendWindowSystemEvents(QFlags<QEventLoop::ProcessEventsFlag>) from /usr/lib64/libQt5Gui.so.5+0xbb
#69  /usr/lib64/libQt5XcbQpa.so.5(+0x728ba) [0x7f914e3138ba]
#70  /lib64/libglib-2.0.so.0(g_main_context_dispatch+0x2ae) [0x7f9150dba6ee]
#71  /lib64/libglib-2.0.so.0(+0x52988) [0x7f9150dba988]
#72  /lib64/libglib-2.0.so.0(g_main_context_iteration+0x2c) [0x7f9150dbaa1c]
#73  0x7f91537c1147 in QEventDispatcherGlib::processEvents(QFlags<QEventLoop::ProcessEventsFlag>) from /usr/lib64/libQt5Core.so.5+0x67
#74  0x7f915376c46b in QEventLoop::exec(QFlags<QEventLoop::ProcessEventsFlag>) from /usr/lib64/libQt5Core.so.5+0x13b
#75  0x7f9153774452 in QCoreApplication::exec() from /usr/lib64/libQt5Core.so.5+0x92
#76  0x7f9154b8a0a6 in Gui::Application::runApplication() from /usr/lib64/freecad/lib/libFreeCADGui.so+0x14c6
#77  freecad(main+0x6a6) [0x404746]
#78  /lib64/libc.so.6(__libc_start_main+0xeb) [0x7f915313008b]
#79  freecad(_start+0x2a) [0x404a4a]