Answer:
This results from the Tapered Section Group data. The section classification does not support the Tapered Section Group function and thus it is recommended to convert tapered section group to individual tapered sections using the 'Convert to Tapered Section' function below. Once they are converted, the processing speed will also be increased because the program calculates the dimensions of the tapered section group whenever opening the program and whenever running the analysis / design.
After you convert it, you should define 'Composite Section for C.S.' and 'Define Flange & Web' again for the tapered sections newly created.