PHP、Fpdf解析错误:使用AddFont()时

<?php
session_start();
include $_SERVER['DOCUMENT_ROOT'] . "/library/fpdf.php";
$pdf = new FPDF('P',"mm",'A4');
$pdf->AddPage();
$pdf->AddFont('DejaVu','','DejaVuSans-Bold.ttf',true);
$pdf->SetFont('DejaVu','',14);
foreach ($_SESSION['settings'] as $settings) {
    $pdf->Cell(130,5,$settings,1,1);
}

$pdf->Output();
?>

警告:输入中存在意外字符:

分析错误[我的ttf文件路径]

如果我删除

$pdf->AddFont('DejaVu','','DejaVuSans-Bold.ttf',true);
$pdf->SetFont('DejaVu','',14);

$pdf->SetFont('Arial','',14);

它工作得很好。