Skin IG / Fast Start Server&Client

I take for example this 2 lines :

LevelPropSpawn(uint32 netId, const std::string& name, const std::string& type, float x, float y, float z) : BasePacket(PKT_S2C_LevelPropSpawn) {
 buffer << netId;

But when i do : HeroSpawn(uint32 netId, uint32 gameId, const std::string& name, const std::string& type, uint32 skinNo) : BasePacket(PKT_S2C_HeroSpawn, netId) { buffer << (uint32)gameId;

It's bugging :/