Hi,
Had a quick look today. Seems that topo has something that dynamo’s geometry doesn’t agree with. I didn’t experience a crash but did get only a null return. What you could try to do is convert the mesh to a toolkit one and run a slight triangle reduction. That prioritizes any small triangles and gets rid of them. For example I try to do a ~10% reduction in the below image and get a mesh that is still very conformant to the original input:
