Self-intersection of surfaces generated when creating a finite element model with shell elements

 I want to model a cross-sectioned column (cross-shaped) using surfaces (shell elements) with 3DEXPERIENCE, but I encountered a self-intersection error. Please advise on a solution.
Ultimately, I want to create an FE model where the cross-shaped intersection point shares nodes with all flanges.

I want to resolve the error occurring during the following steps:
1. From Generative Shape Design, sketch a cross shape with two straight lines intersecting at 90 degrees using wireframe.
2. Extrude the created wireframe to generate a surface.
3. An error related to self-intersection occurs.

Thank you for your assistance

simulia catia