Android : KSOAP2 NUSOAP PHP complexType array android

I'm getting a weird error with my APP.

Everything on my WS works when I call the function to retrieve a array from a * nusoap_client`. If I do that on android, it returns null.

But, if I make my SQL call and it doesn't have any value and return a empty array, my android receive.

With an array with values it returns null and on my response envelope I get the message:

unterminated entity ref (position:TEXT @1:201 java.io.InputStreamReader@something)

My NUSOAP Code:

$server->wsdl->addComplexType(
    "Ticket",
    "complexType",
    "struct",
    "all",
    "",
    array(
        "id" => array("name" => "ID", "type" => "xsd:integer"),
        "status" => array("name" => "status", "type" => "xsd:integer"),
        "titulo" => array("name" => "titulo", "type" => "xsd:string"),
        "descri" => array("name" => "descri", "type" => "xsd:string"),
        "sala" => array("name" => "sala", "type" => "xsd:string"),
        "userOpen" => array("name" => "userOpen", "type" => "xsd:string"),
        "tecnico" => array("name" => "tecnico", "type" => "xsd:string"),
        "horaAbertura" => array("name" => "horaAbertura", "type" => "xsd:string"),
        "horaCompleto" => array("name" => "horaCompleto", "type" => "xsd:string")
    )
);

$server->register("getTickets",
    array("query" => "xsd:string"),
    array("return"=>"tns:TicketArray"),
    $namespace,
    $namespace ."#arrayChamados",
    "rpc",
    "encoded",
    "List Chamados");

PHP code:

function getTickets($query) {
    global $db;

    $findNewTickets = mysqli_query($db, "SELECT * FROM fserv_chamados WHERE userOpen = '$query'");

    if (!$findNewTickets) {
        die("Erro ao localizar: ". mysqli_error($db));
    } else {
        $arr = array();
        while($linha = mysqli_fetch_assoc($findNewTickets)) {
            $arr[] = array(
                'id' => removeAccents($linha['ID']),
                'status' => removeAccents($linha['status']),
                'titulo' => removeAccents($linha['titulo']),
                'descri' => removeAccents($linha['descri']),
                'sala' => removeAccents($linha['sala']),
                'userOpen' => removeAccents($linha['userOpen']),
                'tecnico' => removeAccents($linha['tecnico']),
                'horaAbertura' => removeAccents($linha['horaAbertura']),
                'horaCompleto' => removeAccents($linha['horaCompleto'])
            );
        }
    }
    return $arr;
}