mpdf no output and php errors in mpdf.php - cakephp

Question

I'm trying to generate a pdp file in a cakephp application. Therefore, I use the mpdf library as a vendor. But when I try to make a even very simple output it doesn't work. Then when I use the debug property, it shows php errors in the mpdf.php file.
Here is my source code:
<?php
$mpdf=new mPDF();
$mpdf->WriteHTML('hello');
$mpdf->debug = true;
$mpdf->Output();
exit;
?>
And these are the errors shown in the browser:
Notice (8): Undefined index: BODY [APP\vendors\MPDF54\mpdf.php, line 14242]
Notice (8): Undefined index: BODY>>ID>> [APP\vendors\MPDF54\mpdf.php, line 14288]
Notice (8): Undefined offset: -1 [APP\vendors\MPDF54\mpdf.php, line 14421]
Thank you for your help!

Answer 1

This is not a CakePHP problem but related to the library you're using.
Read about how to use the WriteHTML() method.
http://mpdf1.com/manual/index.php?tid=121
And try passing 2 as the 2nd argument.
$mpdf->WriteHTML('hello', 2);
If this still does not work read the documentation, check the examples there.

Answer 2

This is caused by buggy mpdf code. It depends on error (level "notice") reporting to be switched off (it switches it off itself). But if you handle errors some nonstandard way, it is problem..
I solved it by ignoring errors from mpdf.php file in my custom error handler.
I was using my custom error reporting via set_error_handler();