Why won't the round bends flatten?

Hello all,

So I get a solid inventor model and convert it to sheet metal, we are building this part in five pieces. I have all five parts and everything is good with three of them. The problem I'm having is that two pieces which have round bends will not flatten...solidworks is not allowing me to change radius on one of them. The other gives yet a different error. I'm not sure how to fix these issues.

Any help would be great.

SolidworksSheet Metal