Hmm, yeah, that’s a problem. The “+SIL” stuff is “silicone tent sealant”, and will only stick to silicone coated fabrics, not polyurethane. It used to be called “SilNet,” but I guess they changed the name to “Seam Grip+SIL” for some reason. I will add a note to the instructions warning people not to confuse the two. Unfortunately I think you’ll have to try to remove it if you can.