Shearwall should be used for A12.
The Complete Message:
Structural type A12 is selected in (in X / Y direction) direction. The A12 system should include a shearwall.
A12 structural system is defined as buildings where all earthquake effects are met with high ductility level bond beam (hollow) reinforced concrete walls.
However, the curtain is not defined in the project.
Curtains should be added in the desired direction in accordance with the A12 carrier system in the project .
If a curtain will not be used in the structure, in the Analysis Settings / TBDY 2018 Earthquake Code Wizard, A11 for High Ductility Level Systems and A31 for Systems with Limited Ductility Level can be selected.