Steps to reproduce:

• Create a 3D project using 3D or 3D Extended template
• ->3D View does not show the default cube
• Resetting view does not seem to help
• Adding another model, e.g. sphere works -> it's shown correctly
• Creating a new material and assigning it to default cube model gives "Duplicate property binding" error (see picture)

Additional information:

In general project, adding view3D does seem to work correctly, showing cube in 3D View