Restore Default Layers
This function is available in the Vertex BDapplication.
When you save a drawing, the data of visible layers is saved into it, if the setting Keep Layer Scheme Saved in Drawing is enabled. Next time you open the drawing, the layers are activated according to the saved information. If necessary, you can restore the layers defined as visible in the default layer scheme to be visible in the drawing.
Select Restore Default Layers from the tool strip.