Share Email Facebook Twitter LinkedIn To Unload or Reload an Underlay Click Insert tab Reference. In the File References pane, select a DGN underlay. Right-click, and click Unload or Reload. When unloaded, the DGN underlay is still linked to the drawing file, but it is not displayed in the drawing. Related Concepts About Unloading Underlay FilesAbout Underlays Related Tasks To Attach a DWF or DWFx UnderlayTo Attach a PDF UnderlayTo Attach a DGN UnderlayTo Detach an Underlay Related Reference Commands for Working with Underlays