I think that I have found a bug related to Column design assistant. Namely, if buckling is fixed in a selected direction then the generated CADINP input has an error in it - it is missing a quote. The workaround is to add the missing quote manually
The “Use net cross section” does not work properly either. It is converted to “CTRL NETT TRUE”, but that is not correct input for CADINP. IT should be either “CTRL NETT” or “CTRL NETT YES”