New Client Login Problem "Authenticating"

Guys, I upgraded my League of Legends for the new Client today. The problem is that I am getting stuck in Login Status, it keeps "Authenticating...". I don´t know why but the first time I loaded it, it worked. But after that, while I was at the loot my League of Legends disconnected (WHY?! I dont know) and I got that problem when I tried to reload it. Please help me getting the game back, this is completely ruinning my day!