new Text3D:Barra3D[MAX_PLAYERS];

public OnPlayerDisconnect(playerid, reason)
{
     DestroyDynamic3DTextLabel(Barra3D[playerid]);
     return 1;
}

En onplayerspawn: 

//-CLASE 3DLABEL
	if(!IsPlayerConnected(playerid)) return true;
	if(IsPlayerAdmin(playerid)) return true;
	if(IsPlayerNPC(playerid)) return true;
    DestroyDynamic3DTextLabel(Barra3D[playerid]);
	Barra3D[playerid]=CreateDynamic3DTextLabel("",-1,0.0, 0.0, 0.35,100.0,playerid);

En onplayerupdate
//-CLASE ARRIBA DE LA CABEZA EN 3DLABEL
    new Clase[64];
    if(gTeam[playerid] == TEAM_HUMANOS)
	{
		switch(Clases[playerid])
		{
			case 1: Clase = "{004100}Civil";
			case 2: Clase = "{004100}Gangster";
			case 3: Clase = "{004100}Medico";
			case 4: Clase = "{004100}Policia";
			case 5: Clase = "{004100}Swat";
			case 6: Clase = "{004100}Militar";
		}
    }
	//-CLASE ARRIBA DE LA CABEZA EN 3DLABEL
	if(!IsPlayerConnected(playerid)) return true;
	if(IsPlayerAdmin(playerid)) return true;
	if(IsPlayerNPC(playerid)) return true;
	new data[130];
	format(data,sizeof(data),"%s\n\n",Clase);
	UpdateDynamic3DTextLabelText(Barra3D[playerid],-1,data);