This is a similar situation to Hitomoshi. I was adopting on VB like I always am and came across a Snivy. Picture below.
I was like OMG I am going to be the first person to get one on VB and VR! So I clicked it like anyone would and it gave my the "You can't adopt that Pokemon right now!" screen. Picture below.
I am so pissed at why this keeps happening to me when I come across a Gen V Pokemon that I dont have. It works with a Gen V Pokemon that I already have. (You can see this by the amount of Yunirans and Pururirus that I have) I really want to know why this keeps happening. Anything you say will be helpful! Thank You!