Teambuilder Bug

I recently bought Shaco while in the teambuilder queue and I wanted to try him out. So I cancelled it and started a new one. I set up everything, ready to play but when I pressed on find group a error message popped up. It said something about me not having the Champion, but I clearly did. I then cancelled it and set up everything again but this time I couldn't pick Shaco because it didn't appear in the list of Champions I own.