2D Solid - Axisimmetric - Missing properties and material

Goodmorning,

I'm trying to understand how 2D solid elements work. I want to study the local buckling of a simple aluminium pipe with thin walls. From what I understood, I can use 2D solid elements and model just a section of this pipe .

I've drawn a surface on the XZ plane (Z axis of simmetry). This surface is just a long but very thin rectangle that rapresents the pipe's wall. The pipe is open so no caps etc. I applied the property 2d solid axisimmetric, my costrains and my loads. I then created my mesh with quadx elements. In analysis, I selected SOL105 for bucking analysis.

When I run Nastran, I get some errors, the first one being:

USER FATAL MESSAGE 2011 (TA1)
NO PROPERTY ENTRY FOR ELEMENT TYPE QUADX


Indeed, checking the bdf file, there's no property to be found, nor the material definition!

I tried to group elements with no properties in Patran, but it found none.

What am I doing wrong?

Thank you for helping me out.