Qt3D.ObjGeometryLoader: Missing position index

You can easily reproduce the problem with the following steps:

1. download the file "Temp Chiron Rims.obj" from [here|https://grabcad.com/library/chiron-wheel-and-more-1]
2. save the file inside C:\Qt\Examples\Qt-5.12.2\qt3d\exampleresources\assets\obj
3. open the example "Qt 3D: Shadow Map QML Example"
4. modify Trefoil.qml line 61 from source: "assets/obj/trefoil.obj" to source: "file:/Qt/Examples/Qt-5.12.2/qt3d/exampleresources/assets/obj/Temp Chiron Rims.obj"
5. build and run

After a lot of

Qt3D.ObjGeometryLoader: Missing position index

messages, Application Output console shows

Invalid parameter passed to C runtime function.

Invalid parameter passed to C runtime function.

ASSERT: "!m_thread.isRunning()" in file qqmldebugserver.cpp, line 655

This model can be properly loaded and rendered using MadView3D (which is a 3D viewer based on assimp).

So I think the issue is related to Qt3D itself.