Moonchild3

Hello, so my pokemon (Rhyperior) leveled up and was ready to learn a move "Rock Wrecker". I just let my computer to see something in my house (so I was afk), when I returned, I had to enter my name and my password to login. After that, I could still choose to get Rock Wrecker so I chose it. I did a battle with a random pokemon and what do I see? No Rock Wrecker! ! What can I do to fix that please?