https://bugs.winehq.org/show_bug.cgi?id=47198
--- Comment #31 from aguertin+wine@aguertin.net --- If it helps anyone track this down faster, you do not need to be logged in to reproduce this crash. Simply running C:\Riot Games\League of Legends\Game\League of Legends.exe is enough.
(If the LoL bugsplat dialog appears, the crash did not reproduce. If the wine "System Error" dialog appears, the crash did reproduce. It is about 50-50 for me right now).