https://bugs.winehq.org/show_bug.cgi?id=49013
--- Comment #1 from harry harry+winehq@unheit.net --- Forgot to say, that I use wine-staging. I don't know if the bug only occurs in staging, because I can't run LoL with master.
If I set WINEDEBUG=fixme-all,warn+heap, the exception does not occur anymore. So there's at least a work-around.