Thanks Klaus. I was able to reproduce the crash.
What version of Cesium is the site using?
Could you possibly put together a Sandcastle demo that reproduces the crash? That would make it a lot easier for us to test and figure out what is happening.
I created a stripped down version of the page and in the process removed a rather large library (jqplot) – now I have to rotate the 2D view for quite some time before the error comes up. Unfortunately, I can not put this in Sandcastle due to Same Origin Policies on some resources.
Another interesting observation: When I initialize the viewer with ‘sceneMode: Cesium.SceneMode.SCENE2D’ as in https://ppc.paralog.net/2Dview.html , the tracks are not drawn.