Cant get welded corner tool to work on sheet metal

Hello,

I am making a chassis out of sheet metal 1.5mm thick with a corner radius of 0.75mm and I want to weld down the torn corners. I have tried to do this with the weld corner tool however, it wont work. When I click on a surface with the weld corner tool no preview appears and fails to work when I press the green tick.

I have attached a screenshot and the SLDPRT.

Could someone let me know what I am doing wrong?

Thanks!

EDITED BY MODERATOR: Moved to the Sheet Metal space. Please post in the appropriate space when one exists.

SolidworksSheet Metal