Champion Select Blackout

I don't know how this happen, but these are the details of the event: Upon clicking Accept, the normal box pops up with the number of people accepting. At the last second, me and my friend goes into champion select. My friend can see the champion select normally, with the champions and everything. My screen is replaced with a black screen. It's impossible for me to select a champion at all. However, I'm still able to use the chat thingy (on the bottom of the screen) to talk to my friend, who then tells me that everybody is still picking their champions. After 70 seconds or so, the game crashes for me and returns to the lobby. My friend is also returned to the lobby, and this incident is counted as a dodge.