Stuck in Loading Screen
This is apparently becoming a prevalent glitch. Occurred once before to someone on the enemy team and just recently to someone on my team(or so they claim). Has not occurred to me anytime recently, but has in the past.
Something needs to be done about it because its put one team at a significant disadvantage when the player is completely unaware that the game has started without them. Note, also, that it shows up on everyone else's screens that they have indeed loaded into the game. As much as I can remember, it also shows on your own screen that everything is fully loaded yet you're all stopped at 100%. Since that happens all the time and you get into the game just fine regardless, it's not like you can easily tell. Usually the fix I believe is to relog, but when you don't know that you aren't even in the game, you can't exactly do that until you've decided that its taking much too long.
As it has occurred with multiple people, no, it's probably not an issue on their end, but Riot's.

and wrecked) I press on play and begin the queue for an ARAM game! i got stuck with this bad baby
and was semi-excited to play him. We got into the loading screen and it was working well. Then, for what seemed like an eternity (even though it was probably 10 min.) i decided to look up "getting stuck in a League of Legends loading screen" and this popped up! I looked at the post and the comments and saw that ya'll said you were stuck at 100% so I thought that this didn't apply to me. i waited and the Yi was still at 22% and the last player n the enemy team was "NOT CONNECTED". after another 5 min. i gave up and opened my Task Manager and pressed end-task on the client. i reconnected and it froze again. i did the same proses and reconnected and I FINALLY got in game, at the last 10 seconds of it... THANKS RIOT #Sarcasm