No display on Windows

[fhwedel-hoe]

Symptoms: The OpenSceneGraph widget shows an empty scene. The console shows many warnings:

Warning: Light::apply(State&) - not supported.
Warning: Point::apply(State&) - not supported.
Warning: detected OpenGL error 'invalid enumerant' at after RenderBin::draw(..)
Warning: detected OpenGL error 'invalid enumerant' at end of SceneView::draw()
Warning: detected OpenGL error 'invalid enumerant' after applying GLMode 0x4000

https://github.com/gwaldron/osgearth/issues/1817 suggests that it happens due to poor coding in OpenRoadEd.

This may or may not be related to OpenSceneGraph on my system being unable to read image files:

Error reading file Resources/asphaltAlpha.tga: read error (Could not find plugin to read objects from file "Resources/asphaltAlpha.tga".)
Error reading file Resources/Billboards/LaneWidth.jpg: read error (Could not find plugin to read objects from file "Resources/Billboards/LaneWidth.jpg".)

Any help is appreciated.