I'll add this to our bugs list. Thanks for your report.

I would like some additional information for anyone this happened to: The launcher you are using, if you ever installed any mods for league of legends, how stable your internet connection is, and if your flash and adobe air files are up to date.

I got that a LOT of times, maybe 50%. When someone d/c in the game, it gets up to about 90%. I submitted my logs a couple times. I don't have any mods, a good stable internet connection, the normal launcher and everything is always up to date.

I've had the same problems, for some reason if the case were a troll disconnecting, my launcher either spikes and lags tremendously, or it would freeze for some time until it is alright. I've sent my logs as well and alike Undead, no mods and a good stable connection. Also i might add this started happening some time around last patch, my launcher closes itself after every game and i have to restart, any help?

I get this bug roughly 1/3 of the games I play, and have had it forever D:

I got this bug just BEFORE the change to the new patcher (at lower frequency, now its more frequent, but I do not believe its the new patcher at fault)

THIS STARTED HAPPENING SOON AFTER I STARTED USING ALT+F4 TO CLOSE THE GAME INSTEAD OF PRESSING "VICTORY" (Though since there are many people who say this bug happens even if they press "victory" I don't think this is cause as well.)

I do not get an error message (or I don't know where to look).

The series of events is:
Game Finishes
Fails to connect to the stats (it says "loading stats, press here to skip stats")
Go back to the main screen
Disconnects from PvP.chat
1-2 seconds later session closes

Bump...same problem as the person above me, as well as the others.

I get the same problem, too. Also, I disconnect from PVP Chat frequently.

Yeah, I haven't had any problems of being disconnected, but until the recent patch. I now get closed out and a thing saying "Session Closed" when I'm not even in game....It doesn't affect so far that I've seen for IN GAME play, but it sure does like to pop up before and after on the statistics screen. Another glitch thats been also more frequent that keeps happening now is I go into a game and right off the bat I can't click anything. No shop, no walking, no clicking on spells. Forcing me to disconnect, and then reconnecting. Again know, I haven't had a problem until this recent patch up...

This ****ing bug starting to give me level 1 warning from riot because i was half playing and dc and when i wanna relog the ****ing session closed so i hav to restart the whole **** thing! when i got back to the game, i got report as leave! **** man! i spend so long buying so many runes and my riot points! so what now! disciplinary action! huh! ban my account? fix ur **** bug please and can u like implement a system whether player leave unintentionally or not! i dun wanna risk my **** runes and rp and ip over these stupid bugs!

No mods installed, very stable internet connection, Flash is up to date AFAIK, no clue about Adobe Air. Happens to me every few games. When I play with my brother on the same connection, it will always happen to BOTH of us at the same time.