[Qgis-user] Exception: IllegalArgumentException: Cannot get offset of single-vertex line

[Robin Paulson]

I repeatedly get this error message in the GEOS log window when I use 
the qgis2threejs plugin to render a model of my project.
Exception: IllegalArgumentException: Cannot get offset of single-vertex 
line

As far as I'm aware, I don't have any single-vertex lines; is there any 
way to check easily?

The same project often fails to render, with the following message:
TypeError: QgsNullSymbolRenderer.symbolForFeature(QgsFeature, 
QgsRenderContext): not enough arguments

I wonder if the two are related or coincidental?

I have raised an issue on the qgis2threejs project page.

Does anyone have any ideas?

Cheers,

-- 
robin