This problem illustrates why we developed a Civil 3D workflow system to eliminate this type of problem, as well as other similar type problems. The number rule of our system is to NEVER xref any DWG file that contains a Civil 3D object. Instead, we only use data reference short-cuts for Civil 3D objects. Following that rule makes for more DWG files per project, but it virtually eliminates crashes of Civil 3D, increasing productivity rates in the long run. We are a Public Works Department focusing mainly on roadway improvement projects.