To avoid this, you can deactivate the stability analysis in the ultimate configurations. To do this, select the members concerned and open the "Edit Members" dialog box. You can change the ultimate configuration in the "Design Configurations" tab. In our example, the stability analysis for the bottom chords should be deactivated, since there are only axial tensile forces acting in these members.
You can edit the ultimate configuration via . Create a new configuration (1) and deactivate the stability analysis (2). After the confirmation, you can assign the new configuration to the member.