We are using TCPDF library to generate the PDF file from HTML. It is working fine in Web Brower but when we open and then close it in Adobe Reader it is showing a dialog Do you want to Save Changes xyz file. Visited different forums but can't find the solution to fix this.
You must echo the output function because it returns a string so you should echo that output function as well.
Please see the code snippet below:
$pdf->Output('example_001.pdf', 'D');
echo $pdf->Output;
Or you can try this too:
$pdf->Output('example_001.pdf', 'D');
exit();