here is my mmo.h #ifndef PACKETVER #define PACKETVER 20131222 //#define PACKETVER 20120410 #endif changed this to #ifndef PACKETVER #define PACKETVER 20150916 //#define PACKETVER 20120410 #endif and my packet_db.txt //packet_db_ver: 53 packet_db_ver: default packet_keys_use: default changed this to packet_db_ver: 53 //packet_db_ver: default packet_keys_use: default Then stopped the server, recompiled, started it. Now it says, Failed to connect to server..