L2 Crash Report is made because you dont have enough RAM or GB i usually carry 8GB on me if i open 3 windowed L2 and try to open league of legends at the same time its more easier to kick me from l2 instead league of legends because l2 have this option once you pass your RAM you are kicked out so its not from l2 or dev team its something normal Just upgrade your machine and all good.Also if you playing 3 windowed or full screen characters better for ya to ALT+Enter to make them windowed and once you finish with 1 toon and you leave it AFK farm minimize it less RAM and so on..I even minimize my main from 6,70GB if i minize everything gets to 3,9GB its really good and decent boost for your machine to keep it alive and play something else less heavy game