(lldb) bt * thread #1: tid = 0x2403, 0x00007fff8dd02250 libobjc.A.dylib`objc_msgSend + 16, stop reason = EXC_BAD_ACCESS (code=13, address=0x0) frame #0: 0x00007fff8dd02250 libobjc.A.dylib`objc_msgSend + 16 frame #1: 0x00007fff8b285eca AppKit`+[NSGraphicsContext currentContextDrawingToScreen] + 41 frame #2: 0x00007fff8b2b876a AppKit`-[NSView(NSInternal) _ancestorForStartOfDisplayRecursion] + 43 frame #3: 0x00007fff8b2856c1 AppKit`-[NSView displayIfNeeded] + 116 frame #4: 0x00007fff8b2852ac AppKit`_handleWindowNeedsDisplayOrLayoutOrUpdateConstraints + 738 frame #5: 0x00007fff8b850971 AppKit`__83-[NSWindow _postWindowNeedsDisplayOrLayoutOrUpdateConstraintsUnlessPostingDisabled]_block_invoke_01208 + 46 frame #6: 0x00007fff8fb2a9b7 CoreFoundation`__CFRUNLOOP_IS_CALLING_OUT_TO_AN_OBSERVER_CALLBACK_FUNCTION__ + 23 frame #7: 0x00007fff8fb2a921 CoreFoundation`__CFRunLoopDoObservers + 369 frame #8: 0x00007fff8fb05d88 CoreFoundation`__CFRunLoopRun + 728 frame #9: 0x00007fff8fb056b2 CoreFoundation`CFRunLoopRunSpecific + 290 frame #10: 0x00007fff898240a4 HIToolbox`RunCurrentEventLoopInMode + 209 frame #11: 0x00007fff89823e42 HIToolbox`ReceiveNextEventCommon + 356 frame #12: 0x00007fff89823cd3 HIToolbox`BlockUntilNextEventMatchingListInMode + 62 frame #13: 0x00007fff8b282613 AppKit`_DPSNextEvent + 685 frame #14: 0x00007fff8b281ed2 AppKit`-[NSApplication nextEventMatchingMask:untilDate:inMode:dequeue:] + 128 frame #15: 0x00007fff8b4cc709 AppKit`-[NSApplication _realDoModalLoop:peek:] + 485 frame #16: 0x00007fff8b4cc9ce AppKit`-[NSApplication runModalForWindow:] + 120 frame #17: 0x00007fff8b717db6 AppKit`-[NSSavePanel runModal] + 302 frame #18: 0x0000000105e40750 libqcocoa_debug.dylib`-[QNSOpenSavePanelDelegate runApplicationModalPanel] + 416 at qcocoafiledialoghelper.mm:244 frame #19: 0x0000000105e43d4f libqcocoa_debug.dylib`QCocoaFileDialogHelper::exec() + 47 at qcocoafiledialoghelper.mm:689 frame #20: 0x0000000100359019 libQtWidgets_debug.5.dylib`QDialog::exec() + 441 at qdialog.cpp:528 frame #21: 0x0000000100365861 libQtWidgets_debug.5.dylib`QFileDialog::getOpenFileName(QWidget*, QString const&, QString const&, QString const&, QString*, QFlags) + 465 at qfiledialog.cpp:1775 frame #22: 0x0000000100007f11 standarddialogs`Dialog::setOpenFileName() + 209 at dialog.cpp:372 frame #23: 0x000000010000bf74 standarddialogs`Dialog::qt_static_metacall(QObject*, QMetaObject::Call, int, void**) + 244 at moc_dialog.cpp:123 frame #24: 0x000000010196ee35 libQtCore_debug.5.dylib`QMetaObject::activate(QObject*, int, int, void**) + 2837 at qobject.cpp:3440 frame #25: 0x000000010196e30d libQtCore_debug.5.dylib`QMetaObject::activate(QObject*, QMetaObject const*, int, void**) + 61 at qobject.cpp:3315 frame #26: 0x000000010057cb6b libQtWidgets_debug.5.dylib`QAbstractButton::clicked(bool) + 75 at moc_qabstractbutton.cpp:296 frame #27: 0x00000001001fef17 libQtWidgets_debug.5.dylib`QAbstractButtonPrivate::emitClicked() + 87 at qabstractbutton.cpp:540 frame #28: 0x00000001001fedb9 libQtWidgets_debug.5.dylib`QAbstractButtonPrivate::click() + 409 at qabstractbutton.cpp:533 frame #29: 0x000000010020001c libQtWidgets_debug.5.dylib`QAbstractButton::mouseReleaseEvent(QMouseEvent*) + 236 at qabstractbutton.cpp:1122 frame #30: 0x00000001000ce008 libQtWidgets_debug.5.dylib`QWidget::event(QEvent*) + 632 at qwidget.cpp:7843 frame #31: 0x00000001001ffe28 libQtWidgets_debug.5.dylib`QAbstractButton::event(QEvent*) + 424 at qabstractbutton.cpp:1081 frame #32: 0x00000001002cd1e7 libQtWidgets_debug.5.dylib`QPushButton::event(QEvent*) + 231 at qpushbutton.cpp:686 frame #33: 0x0000000100077a75 libQtWidgets_debug.5.dylib`QApplicationPrivate::notify_helper(QObject*, QEvent*) + 389 at qapplication.cpp:3613 frame #34: 0x000000010007a13f libQtWidgets_debug.5.dylib`QApplication::notify(QObject*, QEvent*) + 3743 at qapplication.cpp:3177 frame #35: 0x000000010191905f libQtCore_debug.5.dylib`QCoreApplication::notifyInternal(QObject*, QEvent*) + 207 at qcoreapplication.cpp:723 frame #36: 0x000000010007febf libQtWidgets_debug.5.dylib`QCoreApplication::sendSpontaneousEvent(QObject*, QEvent*) + 95 at qcoreapplication.h:210 frame #37: 0x00000001000786ff libQtWidgets_debug.5.dylib`QApplicationPrivate::sendMouseEvent(QWidget*, QMouseEvent*, QWidget*, QWidget*, QWidget**, QPointer&, bool) + 943 at qapplication.cpp:2520 frame #38: 0x00000001000fea66 libQtWidgets_debug.5.dylib`QWidgetWindow::handleMouseEvent(QMouseEvent*) + 2166 at qwidgetwindow.cpp:339 frame #39: 0x00000001000fdd8c libQtWidgets_debug.5.dylib`QWidgetWindow::event(QEvent*) + 812 at qwidgetwindow.cpp:137 frame #40: 0x0000000100077a75 libQtWidgets_debug.5.dylib`QApplicationPrivate::notify_helper(QObject*, QEvent*) + 389 at qapplication.cpp:3613 frame #41: 0x000000010007966e libQtWidgets_debug.5.dylib`QApplication::notify(QObject*, QEvent*) + 974 at qapplication.cpp:3044 frame #42: 0x000000010191905f libQtCore_debug.5.dylib`QCoreApplication::notifyInternal(QObject*, QEvent*) + 207 at qcoreapplication.cpp:723 frame #43: 0x0000000100d78a3f libQtGui_debug.5.dylib`QCoreApplication::sendSpontaneousEvent(QObject*, QEvent*) + 95 at qcoreapplication.h:210 frame #44: 0x0000000100d72001 libQtGui_debug.5.dylib`QGuiApplicationPrivate::processMouseEvent(QWindowSystemInterfacePrivate::MouseEvent*) + 1697 at qguiapplication.cpp:1279 frame #45: 0x0000000100d7175d libQtGui_debug.5.dylib`QGuiApplicationPrivate::processWindowSystemEvent(QWindowSystemInterfacePrivate::WindowSystemEvent*) + 61 at qguiapplication.cpp:1125 frame #46: 0x0000000100d5f353 libQtGui_debug.5.dylib`QWindowSystemInterface::sendWindowSystemEventsImplementation(QFlags) + 131 at qwindowsysteminterface.cpp:518 frame #47: 0x0000000100d5f3c0 libQtGui_debug.5.dylib`QWindowSystemInterface::sendWindowSystemEvents(QFlags) + 48 at qwindowsysteminterface.cpp:497 frame #48: 0x0000000105e1de64 libqcocoa_debug.dylib`QCocoaEventDispatcherPrivate::processPostedEvents() + 276 at qcocoaeventdispatcher.mm:1035 frame #49: 0x0000000105e1eb32 libqcocoa_debug.dylib`QCocoaEventDispatcherPrivate::postedEventsSourceCallback(void*) + 66 at qcocoaeventdispatcher.mm:1056 frame #50: 0x00007fff8fae3101 CoreFoundation`__CFRUNLOOP_IS_CALLING_OUT_TO_A_SOURCE0_PERFORM_FUNCTION__ + 17 frame #51: 0x00007fff8fae2a25 CoreFoundation`__CFRunLoopDoSources0 + 245 frame #52: 0x00007fff8fb05dc5 CoreFoundation`__CFRunLoopRun + 789 frame #53: 0x00007fff8fb056b2 CoreFoundation`CFRunLoopRunSpecific + 290 frame #54: 0x00007fff898240a4 HIToolbox`RunCurrentEventLoopInMode + 209 frame #55: 0x00007fff89823d84 HIToolbox`ReceiveNextEventCommon + 166 frame #56: 0x00007fff89823cd3 HIToolbox`BlockUntilNextEventMatchingListInMode + 62 frame #57: 0x00007fff8b282613 AppKit`_DPSNextEvent + 685 frame #58: 0x00007fff8b281ed2 AppKit`-[NSApplication nextEventMatchingMask:untilDate:inMode:dequeue:] + 128 frame #59: 0x00007fff8b279283 AppKit`-[NSApplication run] + 517 frame #60: 0x0000000105e1cf38 libqcocoa_debug.dylib`QCocoaEventDispatcher::processEvents(QFlags) + 1096 at qcocoaeventdispatcher.mm:586 frame #61: 0x000000010191490c libQtCore_debug.5.dylib`QEventLoop::processEvents(QFlags) + 92 at qeventloop.cpp:136 frame #62: 0x0000000101914b25 libQtCore_debug.5.dylib`QEventLoop::exec(QFlags) + 517 at qeventloop.cpp:212 frame #63: 0x0000000101919802 libQtCore_debug.5.dylib`QCoreApplication::exec() + 386 at qcoreapplication.cpp:976 frame #64: 0x0000000100d713c9 libQtGui_debug.5.dylib`QGuiApplication::exec() + 9 at qguiapplication.cpp:1059 frame #65: 0x00000001000791a6 libQtWidgets_debug.5.dylib`QApplication::exec() + 22 at qapplication.cpp:2920 frame #66: 0x000000010000bb8d standarddialogs`main + 669 at main.cpp:61 frame #67: 0x0000000100002a14 standarddialogs`start + 52