Why do I need to buy headshot 2 again for CC5 when I already own it in CC4?

I’ve spent a lot of money on this software, and plugins. Why can’t I use what I already purchased in CC5. I would of waited to buy it if I known this was the case. Is there a way to make Headshot 2 work in CC5?

You don’t need to buy it again. Please click HERE to redeem your plugin upgrades for CC5, Thanks.