Disable Mechanical Structure - Warning Message (AutoCAD Mechanical Toolset)

Why are you seeing this message?

You are attempting to disable mechanical structure, but mechanical structure entities already exist in your drawing. When mechanical structure entities are created, the file's structure is irrevocably changed to contain structure related information. As a result, you cannot disable mechanical structure thereafter.

What can you do?

Choose one of the following courses of action:

• If mechanical structure was enabled during the current drawing session, try Undo.
• Window-select and copy the entire drawing to the Clipboard, and paste in a new drawing that does not have mechanical structure enabled.
• Ignore the mechanical browser and continue using the file as is. Be aware that the prompts for inserting standard parts are slightly different.