There is an unused material, and cross section - Karamba

Hi everybody,

I've been working in some university assignment where we have to design and analyse a gridshell. However I have problems with the assemble componet in Karamba, because it doesn't recognize the cross section and material components. It appears a message saying "There is an unused material" and another one "There is an unused cross section".

I attach the file, where it is explained the problem in a panel as well

Do you how could I fix it? Thank you very much in advance!!

Lorena