Share Email Facebook Twitter LinkedIn To Unload or Reload an Underlay 2013-04-10 Product Documentation Intermediate View Original 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 Tasks To Attach a DWF or DWFx Underlay To Attach a PDF Underlay To Attach a DGN Underlay To Detach an Underlay Related References Commands for Working with Underlays Related Concepts About Unloading Underlay Files About Underlays