Hi,

I want to know how to inspect and resolve.

if i Boss Extrude the drawing it say " Unable to create this feature because it would result in zero-thickness geometry. How can i figure what is wrong ? i mirrored the tangents (yellow lines) but are positioning towards outward when i mirror, even if i did not mirror them same error occur. what could be the cause of this error.

This is the Back View of drawing.

This is Solidworks Model Mania 2000 Design Project