You said that you have a shape ready to be extruded with “pedit” ( did you really close your shape ? ).

You can convert a selection of lines, arcs, ellipses, etc into a closed shape with the command “REGION” that will make you sure that your shape is OK to be extruded that’s to say without lines in double or not jointed etc…

Read the Autocad message on the command line : NOT-OK : 0 regions created, OK : 1 ( or X ) regions created.

If your region is OK, make sure that the path that you will use is OK for the region to be extruded.

Read the error message given by Autocad when trying to extrude your shape.

If it says that the shape is impossible to be extruded with a message like :

The lateral  curve doesn’t cut the surface it means that your path has radius to little to “bend” your shape :

The distance between your path centreline and the external of your shape is giving you the minimum radius.

In that case you will have to extrude your shape on paths with extra lengths and “SUBTRACT” or “CHAMFER” the extremities.

Example in the real life : You make a frame with tubes, two possibilities :

1 – You bend the tubes