This article provides the system requirements for AutoCAD 2010. This article provides the system requirements for AutoCAD 2010 Skip to main content. Deutsch; English. Get answers fast from Autodesk support staff and product experts in the forums. Visit AutoCAD Forums. Find related content.
• 72 Answers SOURCE: The 'circular reference' indicates that the xref you are pulling in is also xrefing the drawing file you are in which creates this circular reference to each other. The error message is only a warning and does not prevent you from working and saving changes. To get rid of the error message, close the primary drawing file and then open the reference drawing and DETACH the xref that is linked to your primary drawing. Save the changes and then open the primary drawing file again to see if the error was resolved. 
Posted on Jun 16, 2009.