If your .zip file is an unofficial fan translation or a fix for the Japanese version:
: Many users report that you must run the game as an Administrator or use the LAUNCHER.exe inside the folder for patches/saves to work correctly. 2. If you are experiencing text or font bugs File: Xanadu.Next.zip ...
: You may need a tool like quickbms with a specific script to decompress these files before the text becomes readable in a standard hex or text editor. If your