ahogy létrehoztad az n-t 24 karakterrel,oda MAX_PLAYER_NAME-t kell írni.
vagyis:
new n[MAX_PLAYER_NAME];
 

#include <a_samp>
#include <dini>
new bool:ElsoBelepes[MAX_PLAYERS];
public OnPlayerConnect(playerid)
{
    ElsoBelepes[playerid] = true;
    return 1;
} 
public OnPlayerSpawn(playerid)
{
    if(ElsoBelepes[playerid])
    {
        new n[24],f[64];
        GetPlayerName(playerid,n,24);
        format(f,64,\"Mentések/%s.ini\",n);
        if(dini_Exists(f)) {
            SetPlayerSkin(playerid,dini_Int(f,\"Skin\"));
           SetPlayerPos(playerid,dini_Float(f,\"Xpos\"),dini_Float(f,\"Ypos\"),dini_Float(f,\"Zpos\"));
        }
        ElsoBelepes[playerid] = false;
    }
    return 1;
}
public OnPlayerDisconnect(playerid,reason)
{
    new n[24],f[64],Float:X,Float:Y,Float:Z;
    GetPlayerName(playerid,n,24);
    format(f,64,\"Mentések/%s.ini\",n);
    dini_Create(f);
    dini_IntSet(f,\"Skin\",GetPlayerSkin(playerid));
    GetPlayerPos(playerid,X,Y,Z);
    dini_FloatSet(f,\"Xpos\",X); dini_FloatSet(f,\"Ypos\",Y); dini_FloatSet(f,\"Zpos\",Z);
    return 1;
}