Invalid Final Boss Veigar Skin [Client]

Just purchased the Final Boss Veigar skin after queuing up for a team-builder game. When I try and search for teammates, I keep receiving an error message that reads "INVALID_SKIN". After clicking OK on the popup, another one pops up stating "We didn't hear back from the server. Please try again". Then, after clicking OK on this second popup, I cannot start the game, even if I change skins. The problem persists after restarting with a new queue, as well as restarting the LoL Client. The bug has persisted every time I have tried to play with this skin in a team-builder game. Can anyone help me with this???? Thanks!