[Burning]

Код:

public GiveScore(playerid)
{
    new message[16];
    SetPlayerScore(playerid, GetPlayerScore(playerid) +1);
    format(message,sizeof(message),"UP| LEVEL UP (%d)",GetPlayerScore(playerid));
    SendClientMessage(playerid,COLOR_GREEN,message);
    return 1;
}

If it will fail try raising new message[16] to more, for example message[20] and on..