Selling my first champ after 1st round... Stuck on sell screen and now I have no champs.

I always sell my first champ after 1st minion wave for the gold advantage. I've never had a problem until now. The champ buying screen got bugged on the selling screen and I have nothing to sell, and nothing to buy. I automatically have been losing every round because I have no champs. This is really annoying especially when it's a ranked match - and it literally happened after stage 1-1. This definitely isn't the first time this has happened, but I always had champs that I could sell to get out of that bugged screen. FIX THIS PLEASE.