Columns with a dimension ratio greater than 6 should be modeled as walls.
In TBDY 2018 clause 7.6.1.1 , curtains are vertical structural system elements whose long edge to thickness ratio is at least six.
Accordingly, if the size ratio of a vertical element is greater than 6, it can be a curtain.
You are faced with this message because the vertical element with a dimension ratio greater than 6 in your project is defined using the "Column command".
Solution
Delete the floor and the column named, whose dimension ratio is greater than 6, and redefine it with the "Pitch command".