Unable to thicken the surface

Hello fellow users,

I know this is common question but the other posts I've read didn't have the answer. I've looked at the Check feature and checked the minimum radius curvature and used a thickness less than that and the part still didn't thicken.

I've attached the part. It is a very simple part but the problem persists.

Any help would be greatly appreciated...

Thanks,

David

SolidworksGeneral