Cannot bend in the other direction ???

Hi all,

Another newbie question for you.

I am just playing around with the sheet metal part of SW and designing myself some vehicle jack-stands. For the stand base plates I have opted for some 3mm sheet metal 200mm square which I intend to apply a 8 degree diagonal crease (bend) across the face for support. I have successfully applied one bend corner to corner just by sketching the line and applying the bend. But now, I cannot apply the same process for the intersecting bend as I am unable to select one of the corners of my part now for some reason? Basically, what I am trying to achieve is what you might consider as a 200mm square plate laying on it's face but has the appearance of a VERY shallow pyramid. Where am I going wrong?     (Drawing attached)

SolidworksSheet Metal