Query: Microsoft Loopback Adapter

I wasn't aware that the normal game used any such loopback adapter that would need to be disabled. As others have stated previously, this sounds like it would have to have something to do with a private server that makes use of one of these. I know you said that isn't the case, but I would maybe hint at him to perhaps dig around some of those communities to find the answer, as they're more likely to know.

Here's a completely random "fix": a friend of mine had an issue with accessing Nexon's website a long time ago back when he played the game, and claimed he was able to fix it by taking something out of his Hosts file. Perhaps look in there? YMMV.