v4.0.3 Barcode - Page 1

Simply this.

Notice: String offset cast occured in html2pdf_v4.03/_tcpdf_5.0.002/barcodes.php on line 1156
...

$seq .= '01010'; // center guard bar
for ($i = $half_len; $i < $len; ++$i) {
$seq .= $codes['C'][$code{$i}];
}

...

Solved!

The problem is due to the new error in php 5.4

In the file barcodes.php aorund line 1143

transform this:
$half_len =ceil($len / 2);


in this:
$half_len =(int)ceil($len / 2);


And all come back to life. under php 5.4