in the name of GOD .
I have a problem with Composite Design in Revit Structure 2013.
I select a steel beam and then run "Composite Design" but the error message is appear (see attached image 1 ).
after I click "OK" an error appear ( see attached image 2 ).
please help me to solve my problem to Design a Composite.
thanks beforehand for your appropriate answers
You can only use the composite design extension for AISC W-Shape Members.