I'm a top 60 player and I have virtually been disconnected from the Nexon server for the past 5 days. I can't attack and I can't defend. If it's happened to me it most have happened to others.
I think everyone was in the same boat - I'm way down the list of players, but had the same problems. Think it was to do with the Server upgrade, then the client upgrade.
Good news is that I'm back to normal pretty much now - still crashes a bit thou. Sigh.