Dear all, I have generated a mesh of the gmesh format around a 3D cylinder(radius=0.5). When I perform the following command: ./MeshConvert -m cyl:surf=16,17:r=0.5:N=10 cylinder_straightlines.xml cylinder_highorder.xml The following error message is generated: Fatal : Level 0 assertion violation This function is only valid for shape type geometries terminate called after throwing an instance of 'ErrorUtil::NekError' what(): Level 0 assertion violation This function is only valid for shape type geometries Can anybody tell me how to solve this problem? The msh and cylinder_straightlines.xml files are attached. Thank you! Best Jian Yu