The first thing you can do is, going to your AV (anti-virus) and set an exception for l2.exe or whole l2 folder.
why?
because, after last update there seems to have implemented new security features witch look up your currently running programs, and make it look like a virus/trojan.
why?
because, after last update there seems to have implemented new security features witch look up your currently running programs, and make it look like a virus/trojan.