tcpdf $pdf->Output('out.pdf', 'I'); gone bad - tcpdf

Question

I'm trying to learn TCPDF but I`m stucked in a strange problem, it's my code picked up by the example.
require_once('../tcpdf.php');
ob_start();
// create new PDF document
$pdf = new TCPDF("P","mm","A4",true,"UTF-8",false);
// set document information
$pdf->SetCreator(PDF_CREATOR);
$pdf->SetAuthor('User');
$pdf->SetTitle('TCPDF');
$pdf->SetSubject('TCPDF Tutorial');
$pdf->SetKeywords('TCPDF, PDF, example, test, guide');
// set default header data
$pdf->SetHeaderData(PDF_HEADER_LOGO, PDF_HEADER_LOGO_WIDTH, PDF_HEADER_TITLE.' 001', PDF_HEADER_STRING, array(0,64,255), array(0,64,128));
$pdf->setFooterData(array(0,64,0), array(0,64,128));
// set header and footer fonts
$pdf->setHeaderFont(Array(PDF_FONT_NAME_MAIN, '', PDF_FONT_SIZE_MAIN));
$pdf->setFooterFont(Array(PDF_FONT_NAME_DATA, '', PDF_FONT_SIZE_DATA));
// set default monospaced font
$pdf->SetDefaultMonospacedFont(PDF_FONT_MONOSPACED);
// set margins
$pdf->SetMargins(PDF_MARGIN_LEFT, PDF_MARGIN_TOP, PDF_MARGIN_RIGHT);
$pdf->SetHeaderMargin(PDF_MARGIN_HEADER);
$pdf->SetFooterMargin(PDF_MARGIN_FOOTER);
// set auto page breaks
$pdf->SetAutoPageBreak(TRUE, PDF_MARGIN_BOTTOM);
// set image scale factor
$pdf->setImageScale(PDF_IMAGE_SCALE_RATIO);
// set some language-dependent strings (optional)
if (#file_exists(dirname(__FILE__).'/lang/eng.php')) {
require_once(dirname(__FILE__).'/lang/eng.php');
$pdf->setLanguageArray($l);
}
// ---------------------------------------------------------
// set default font subsetting mode
$pdf->setFontSubsetting(true);
// Set font
// dejavusans is a UTF-8 Unicode font, if you only need to
// print standard ASCII chars, you can use core fonts like
// helvetica or times to reduce file size.
//~ $pdf->SetFont('dejavusans', '', 14, '', true);
// Add a page
// This method has several options, check the source code documentation for more information.
$pdf->AddPage();
// set text shadow effect
$pdf->setTextShadow(array('enabled'=>true, 'depth_w'=>0.2, 'depth_h'=>0.2, 'color'=>array(196,196,196), 'opacity'=>1, 'blend_mode'=>'Normal'));
$html = "ASD";
$pdf->writeHTML($html, true, false, true, false, '');
ob_end_clean();
$pdf->Output('prova.pdf', 'I');`
When the PHP reach the Output command something gone wrong, it doesn't open the PDF page on the browser but print a strange output, like if a open a PDF file with a text editor.
Here I use writeHTML(), but is the same with Image(), I've already try it.
Where am I doing wrong?

Answer 1

You need a Content-Disposition header.
See this other thread: PHP Content-Disposition: attachment / Content-Type

Answer 2

i tested things that you did, i working for me, i thing if download the tcpdf API again and replace it with your current folder.
and also about image: make sure that your image type is .jpg as
$html = "ASD
<img src="project path/images/image.jpg"/>
";