Custom built up shape RAM elements

I have geometrical properties for a custom shape (C8x13.75 with 2-1/4"x8" plates on both top and bottom). I created a "Gen shape" in RAM Elements and assigned it to a beam that I am studying. RAM elements is able to analyze it, however, it is unable to design it. Is there a reason it is not able to design it?

Any insights on this matter is appreciated!

Thank you!