Poro King Wont Start

Okay, so I logged on and noticed that they added a limited edition game mode and I decided to try it. Made it through champion select just fine. Time runs out and --- this is where it ends. Main client closes like it always does before switching to full screen, but then it never switched. Ive logged out and back on twice, pressing reconnect both times. Ive recently done some personal maintenance work on my computer, is this something I changed or is this something that other summoners are experiencing as well? Pls help, bump. Just spent 20$ and havent gotten to use any of it. D: