Take care when naming your tables. If you use the same table name in more than one source drawing, be sure that all tables with same name have the same fields and field types. If your current drawing has more than one source drawing with the same object data table name, AutoCAD Map 3D uses the object table definition (or structure) for the first drawing that you activate. If the other source drawings have tables with the same name but with different fields, you cannot use those tables in the current drawing. If necessary, you can rename or redefine an object data table.