What is a DLO file? In Autodesk 3ds Max, .dlo files are plugin files that extend the functionality of the software. These plugins can provide additional tools, features, or support for specific file formats. Once the plugin is loaded, you should be able to access its features within the 3ds Max interface. This might involve new tools, modifiers, or import/export options, depending on the purpose of the plugin. DLO File Format DLO files are binary files that comply with Autodesk 3ds Max.