Next Order DNA Digivolve Problem

Having a bit of trouble and wondering if anyone else has had this problem. I just DNA'ed into Paildramon and the rookie veemon won't digivolve back into Exveemon even though he has a "fix" for all the mons in the tree. He keeps dying which I assume will totally mess us my inheritance gains for the next mon. Anybody else have this problem? I feel like it may have something to do with waiting to long to DNA and maybe the veemon is too old to digivolve.