Chamfer edge

Hello I wonder if anyone can help me.

I am trying to chamfer the meeting of two edges on what might be called a space helmet I have just modelled.

The original form is an open Polysurface.

I use commands Sold> Fillet Edge> Chamfer Edge

I realise Chamfer handle is critical in this process. When asked to edit it I simply press return to accept default.

I get the message “failure in building corners”.

If you also look at attached image you can see something I was not hoping for.

Does anyone have any idea what is going wrong?

I suspect there may be a kink in the edge, or the fillet radius it too big for the surrounding surfaces. Either way, it appears the fillet is falling off the rails.

We will need the 3dm file to check it.

Space helmet 22 10 21b.3dm (438.4 KB)

Got it to work! Strangely if I use pull down menu from above Sold> Fillet Edge> Chamfer Edge it does not work.

But if I use icon menu from side solid tools> chamfer it does work.