Board Thread:Questions and Answers/@comment-104.179.61.245-20150903014854/@comment-6697950-20150904150234

Oh, there are plenty of such errors to go around. I've heard of this error before. In this case, the 50th floor was already cleared by the time of the story in the web version, but since this was changed in the published version, this reference should have been changed to "Yggdrasil City" instead. This error seems to have been fixed in a later reprint.