Boundary condition error

Dear all,I’m studying the “three dimensional fluidzed bed” tutorial, and there was an error when I ran it. I don’t know how to solve this error. Can someone explain the reason for this.
three dimensional fluidzed (1.0 MB)

When you create the “walls” region, make sure the “cylinder” check box is checked. I think the figure that shows the setting is incomplete.

Thank you very much. I tried again. The error report was resolved.