It's a while since I solved one of these, but I think I'm right in saying that there are two identical-looking edge pieces to the one you have flipped?
If so, try exchanging it for one of those.
It's not solvable. You'll have to take the piece out and reinsert it correctly. (If you ignore the colours on the edge pieces, every quarter turn flips four edges, so there will never be an odd number of flipped edges.)
It's a while since I solved one of these, but I think I'm right in saying that there are two identical-looking edge pieces to the one you have flipped?
If so, try exchanging it for one of those.