Editable Polys extrude as hollow shapes

[MBrownFPTRT]

I create a curved top rectangular shape using the Line tool and a Bezier line at the top to create the curve. I convert this into an "editable poly," but it is anything but. When I extrude it, the back is completely open. It is like a hollow, metal can with the back removed. This should be pretty simple, but it is not. Why would the face not extrude, but the outlines do? Can anyone explain why this is not working? I am using the "Extrude" tool in what I think Autodesk calls "rollouts," but are actually floating palettes. See the images (assuming they post properly). Thank you for any help on this. It is sort of important to be able to extrude polylines and polygons. For some reason, the Extrude modifier is missing from the Modifier List, where modifiers pop in and out like sub-atomic particles.

Thank you!

MHBrown

[Diffus3d]

Try using an extrude modifier on your line before converting it to an Edit Poly.  Otherwise, your line converted to poly creates a face with only 1 side.   It's trivial to select that back border on your current model with the border subobject selection and hit "Cap" to close it if you want to keep using your current workflow.  

The modifiers pop in and out based on what kind of geometry or object you have selected, there's no mystery to it.  A line can use an extrude modifier, but a poly cannot because there is already an extrude operation in the edit polys.  

Best Regards,