Shell not working

 From:  rhodesy
I've just been trying to create a quick chair design and I have made the seat/back shape and now wish to shell it. Unfortunately nothing happens when i run the command. The chair isn't to any specific scale just now but I know what sort of range i should be scaling it by by making measurements within the scene. There doesnt seem to be anything too demanding with the shape and there aren't any tight creases so im a bit stumped - i thought shell had been tuned up relatively recently. Using June23 beta.

Cheers for any help here,