The lightColor property of ModelGraphics cannot be set

I want to set the lightColor property value of ModelGraphics, but when I do, I get this error:

modelGraphics.lightColor = new Cesium.ConstantProperty(

Ask the community to help see, what is the problem? thank you

Hi @WaterSeeding,

When I try this in Sandcastle, I can set the light color accordingly.

Would you mind providing a more complete code example so we can reproduce the error?