Border collisions
Many levels contain invisible walls that don’t belong to a static model or a dynamic clip. These walls are generated by a CLevelBorderComponent, attached to an object in the Other group. It provides optimised border collisions for the entire level.

Enable the Border Collisions camera layer to see them.
Editing these collisions is not supported. Deleting the parent object removes them entirely; you can then rebuild walls where you need them with dynamic clips.