I haven't been able to find any useful info on this problem. I am running Civil 3D 2009. I get this error message while trying to either plot, plot preview, or page setup. The message appears and the only way out is with task manager. To makes matters worse it is only doing it when working with files in a particular directory. All these files have in common that they have been generated using civil 3D tools, ie. grading, corridors, alignments etc. Any help would be greatly appreciated.