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MDI is a new engineering environment feature that allows the user to edit multiple displays or scripts at the same time. This makes it easier to copy content between documents, facilitate comparison between different documents, and decrease the switching time between documents that are being edited.

This feature also allows you to close a document that is open in the Last Document Bar, which is located at the top of the screen. 

Draw Environment

In the Draw Editor tab (Edit -Draw-Drawing), the MDI enable button is in the toolbar located at the top of the display.

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In the Scripts environment (Edit -Scripts-Tasks/Classes), you should see the MDI enable button is in the toolbar located on the top of the display.

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This feature provides easy access to the recently used information, enhances user experience, and improves the workflow.

This feature also allows you to close a document that is open in the last document bar.