I want to create a complete circle with a wall but every time I try, the entire thing disappears.
While it is not possible to create a closed circle using a single curved wall or railing, a completely circular wall can be modelled using two wall segments rather than one.
To create a circular wall
Open the plan in which you would like to create a circular wall or select File> New Plan to open a new, blank plan.
Select Build> Curved Wall from the menu and select the desired wall or railing type from the Curved Wall sub-menu.
Click and drag a wall arc segment.
Click on the wall segment to select it and use the triangular Curvature edit handle that displays along the arc to adjust the amount of curvature as needed.
Select Build> Wall> Break Wall from the menu then click once along the curved wall to place a break at that location.
Do not place the wall break at a location where you will be placing a window, door or fireplace; other than that consideration, exact placement of the wall break is not important.
Click on the Select Objects tool to select it, then click on the curved wall on either side of the wall break that was just placed. Notice that only the side of the wall that you clicked on is selected.
Place your cursor over the end edit handle and drag the handle to extend the curved wall segment until it joins with the end of the other segment.
When you release the mouse button, the two wall segments form a closed circle.