Hello all, I am doing a SOL 600 analysis but Nastran gives me an error of "zero thickness" in some elements. Obviously, I checked those elements and they have properly defined their properties so I don't know what can I do. I've done a lot of linear and nonlinear static analysis in that model and all of them have run okey, therefore I suppose that the model is well constituted, where could be the problem? The model is all formed by Quad4 elements and Patran version is 2010. Thanks in advance.