I am not able to extrude closed polyline shapes. I get the following message:
Cannot create solid from open curve.
Cannot sweep or extrude non-planar objects.
Unable to extrude the selected object.
Other folks have opened my drawing – some can extrude, some get the same or similar message. I’ve tried re-building the shapes to extrude. It helped with one thing this morning and now it won’t extrude again.
Try posting in the AutoCAD forum. This is for network licensing. You'll get a quicker response there.
This is why I love Darren.