I have a simple cone with vertical girders and ring stiffeners. The bottom of the cone in fixed whereas top is fixed in 5 dofs except for vertical direction in which 1kN point load is applied by means creating a RP and connecting it with cone top nodes through kinematic coupling. The cone is meshed with primarily S4R elements, with few S3R. Got non linear material property. The model solves fine without NLGEOM but fails to converge with NLGEOM. The inp file is attached along with short visual of problem description. 

​​​​​​​