Crash in QmlDesigner::FormEditorView::rootNodeTypeChanged

0   libQmlDesigner.dylib            0x12018726c         QmlDesigner::FormEditorView::rootNodeTypeChanged (formeditorview.cpp:274)
1   libQmlDesigner.dylib            0x120525540         QmlDesigner::Internal::ModelPrivate::notifyRootNodeTypeChanged (model.cpp:442)
2   libQmlDesigner.dylib            0x120532828         QmlDesigner::Internal::ModelPrivate::changeRootNodeType (model.cpp:1221)
3   libQmlDesigner.dylib            0x120508148         QmlDesigner::AbstractView::changeRootNodeType (abstractview.cpp:802)
4   libQmlDesigner.dylib            0x1205f9684         QmlDesigner::Internal::ModelAmender::typeDiffers (texttomodelmerger.cpp:2168)
5   libQmlDesigner.dylib            0x1205ebb40         QmlDesigner::Internal::TextToModelMerger::syncNode (texttomodelmerger.cpp:1263)
6   libQmlDesigner.dylib            0x1205e8a70         QmlDesigner::Internal::TextToModelMerger::load (texttomodelmerger.cpp:1178)
7   libQmlDesigner.dylib            0x1205c3bc0         QmlDesigner::RewriterView::amendQmlText (rewriterview.cpp:508)
8   QtCore                          0x106fcbd5c         [inlined] QtPrivate::QSlotObjectBase::call (qobjectdefs_impl.h:363)
9   QtCore                          0x106fcbd5c         doActivate<T> (qobject.cpp:3972)
10  QtCore                          0x106fdeb84         [inlined] QTimer::timeout (moc_qtimer.cpp:244)
11  QtCore                          0x106fdeb84         QTimer::timerEvent (qtimer.cpp:259)
12  QtCore                          0x106fc4834         QObject::event
13  QtWidgets                       0x105e83e4c         QApplicationPrivate::notify_helper (qapplication.cpp:3313)
14  QtWidgets                       0x105e84eb4         QApplication::notify (qapplication.cpp:3264)
15  QtCore                          0x106f82f8c         QCoreApplication::notifyInternal2 (qcoreapplication.cpp:1026)
16  QtCore                          0x1070e2d1c         QTimerInfoList::activateTimers (qtimerinfo_unix.cpp:610)
17  libqcocoa.dylib                 0x105d8a44c         [inlined] QCocoaEventDispatcherPrivate::processTimers (qcocoaeventdispatcher.mm:95)
18  libqcocoa.dylib                 0x105d8a44c         QCocoaEventDispatcherPrivate::activateTimersSourceCallback (qcocoaeventdispatcher.mm:89)
19  CoreFoundation                  0x19c73ca18         <unknown>
20  CoreFoundation                  0x19c73c9ac         <unknown>
21  CoreFoundation                  0x19c73c71c         <unknown>
22  CoreFoundation                  0x19c73b320         <unknown>
23  CoreFoundation                  0x19c73a888         <unknown>
24  HIToolbox                       0x1a5e0ffa0         <unknown>
25  HIToolbox                       0x1a5e0fde4         <unknown>
26  HIToolbox                       0x1a5e0fb2c         <unknown>
27  AppKit                          0x19f9bc424         <unknown>
28  AppKit                          0x19f9bb5b4         <unknown>
29  AppKit                          0x19f9af9e4         <unknown>
30  libqcocoa.dylib                 0x105d8ae38         QCocoaEventDispatcher::processEvents (qcocoaeventdispatcher.mm:394)
31  QtCore                          0x106f8bff4         [inlined] QEventLoop::processEvents (qeventloop.cpp:100)
32  QtCore                          0x106f8bff4         QEventLoop::exec (qeventloop.cpp:182)
33  QtCore                          0x106f83640         QCoreApplication::exec (qcoreapplication.cpp:1347)
34  Qt Design Studio                0x10459f7a4         main (main.cpp:760)
35  dyld                            0x19c333e50         <unknown>