Because the character name you entered has a person who entered this name earlier than you in MapleStory.
That is to say, if the character name is the same, this name cannot be used again, so you must enter another name.
"MapleStory Online" is a 2D side-scrolling online game produced and developed by South Korea's WIZET and NEXON. It was officially launched in mainland China on July 24, 2004 and is operated by Shanda Network.