Does anybody know what causes this error? I have a single machine which is proving problematic when trying to plot to an HP 1050C. Whenever I select it in the page setup, I get this eror message. I can print to it from Word etc and all other AutoCAD machines can plot to it without problems. I have tried uninstalling and re-installing but with no joy. I have searched all my usual places but can find no details on this particular 'Unknown' Error Code