There is an exploit in catacombs underground forrest. It's a level 45 quest in Midgards underground forrest. you go talk to the guy and he tells you to find the named inconnu in the inconnnu crypt. You go find him and kill him, then telemport back to talk to the guy... as soon as you get your exp ( which equals alot at level 49 ) you cancel the quest in your journal before talking to him any further and can redo the quest.
This is bannable.