Title: mPDF Error Last modified: February 2, 2018 --- # mPDF Error * Resolved [muhammadpuspaceno](https://wordpress.org/support/users/muhammadpuspaceno/) * (@muhammadpuspaceno) * [8 years, 3 months ago](https://wordpress.org/support/topic/mpdf-error-3/) * Hello Guys! I Just Installed DK-PDF on my local machine to test it so I can start a project with it soon. I created a sample page so I could test the conversion to PDF through the PDF button. However, when I click on the button, I get the following error: * `mPDF error: Some data has already been output to browser, can't send PDF file` * I’m quite lost here so would love to get some help. I’m using DK-PDF version 1.9.3 and PHP version 7.2.0. Here’s the full stack trace in case you need it: * ``` Warning: Illegal string offset 'ID' in C:\xampp\htdocs\wordpress\wp-content\plugins\dk-pdf\includes\mpdf60\classes\cssmgr.php on line 1136 Warning: Cannot assign an empty string to a string offset in C:\xampp\htdocs\wordpress\wp-content\plugins\dk-pdf\includes\mpdf60\classes\cssmgr.php on line 1136 Warning: Illegal string offset 'LANG' in C:\xampp\htdocs\wordpress\wp-content\plugins\dk-pdf\includes\mpdf60\classes\cssmgr.php on line 1139 Warning: Cannot assign an empty string to a string offset in C:\xampp\htdocs\wordpress\wp-content\plugins\dk-pdf\includes\mpdf60\classes\cssmgr.php on line 1139 Warning: Illegal string offset 'ID' in C:\xampp\htdocs\wordpress\wp-content\plugins\dk-pdf\includes\mpdf60\classes\cssmgr.php on line 1190 Warning: Illegal string offset 'LANG' in C:\xampp\htdocs\wordpress\wp-content\plugins\dk-pdf\includes\mpdf60\classes\cssmgr.php on line 1190 Warning: Illegal string offset 'ID' in C:\xampp\htdocs\wordpress\wp-content\plugins\dk-pdf\includes\mpdf60\classes\cssmgr.php on line 1136 Warning: Cannot assign an empty string to a string offset in C:\xampp\htdocs\wordpress\wp-content\plugins\dk-pdf\includes\mpdf60\classes\cssmgr.php on line 1136 Warning: Illegal string offset 'LANG' in C:\xampp\htdocs\wordpress\wp-content\plugins\dk-pdf\includes\mpdf60\classes\cssmgr.php on line 1139 Warning: Cannot assign an empty string to a string offset in C:\xampp\htdocs\wordpress\wp-content\plugins\dk-pdf\includes\mpdf60\classes\cssmgr.php on line 1139 Warning: Illegal string offset 'ID' in C:\xampp\htdocs\wordpress\wp-content\plugins\dk-pdf\includes\mpdf60\classes\cssmgr.php on line 1190 Warning: Illegal string offset 'LANG' in C:\xampp\htdocs\wordpress\wp-content\plugins\dk-pdf\includes\mpdf60\classes\cssmgr.php on line 1190 Warning: A non-numeric value encountered in C:\xampp\htdocs\wordpress\wp-content\plugins\dk-pdf\includes\mpdf60\mpdf.php on line 31965 Warning: A non-numeric value encountered in C:\xampp\htdocs\wordpress\wp-content\plugins\dk-pdf\includes\mpdf60\mpdf.php on line 31965 Warning: Illegal string offset 'ID' in C:\xampp\htdocs\wordpress\wp-content\plugins\dk-pdf\includes\mpdf60\classes\cssmgr.php on line 1136 Warning: Cannot assign an empty string to a string offset in C:\xampp\htdocs\wordpress\wp-content\plugins\dk-pdf\includes\mpdf60\classes\cssmgr.php on line 1136 Warning: Illegal string offset 'LANG' in C:\xampp\htdocs\wordpress\wp-content\plugins\dk-pdf\includes\mpdf60\classes\cssmgr.php on line 1139 Warning: Cannot assign an empty string to a string offset in C:\xampp\htdocs\wordpress\wp-content\plugins\dk-pdf\includes\mpdf60\classes\cssmgr.php on line 1139 Warning: Illegal string offset 'ID' in C:\xampp\htdocs\wordpress\wp-content\plugins\dk-pdf\includes\mpdf60\classes\cssmgr.php on line 1190 Warning: Illegal string offset 'LANG' in C:\xampp\htdocs\wordpress\wp-content\plugins\dk-pdf\includes\mpdf60\classes\cssmgr.php on line 1190 Warning: Illegal string offset 'ID' in C:\xampp\htdocs\wordpress\wp-content\plugins\dk-pdf\includes\mpdf60\classes\cssmgr.php on line 1136 Warning: Cannot assign an empty string to a string offset in C:\xampp\htdocs\wordpress\wp-content\plugins\dk-pdf\includes\mpdf60\classes\cssmgr.php on line 1136 Warning: Illegal string offset 'LANG' in C:\xampp\htdocs\wordpress\wp-content\plugins\dk-pdf\includes\mpdf60\classes\cssmgr.php on line 1139 Warning: Cannot assign an empty string to a string offset in C:\xampp\htdocs\wordpress\wp-content\plugins\dk-pdf\includes\mpdf60\classes\cssmgr.php on line 1139 Warning: Illegal string offset 'ID' in C:\xampp\htdocs\wordpress\wp-content\plugins\dk-pdf\includes\mpdf60\classes\cssmgr.php on line 1190 Warning: Illegal string offset 'LANG' in C:\xampp\htdocs\wordpress\wp-content\plugins\dk-pdf\includes\mpdf60\classes\cssmgr.php on line 1190 Warning: Illegal string offset 'ID' in C:\xampp\htdocs\wordpress\wp-content\plugins\dk-pdf\includes\mpdf60\classes\cssmgr.php on line 1136 Warning: Cannot assign an empty string to a string offset in C:\xampp\htdocs\wordpress\wp-content\plugins\dk-pdf\includes\mpdf60\classes\cssmgr.php on line 1136 Warning: Illegal string offset 'LANG' in C:\xampp\htdocs\wordpress\wp-content\plugins\dk-pdf\includes\mpdf60\classes\cssmgr.php on line 1139 Warning: Cannot assign an empty string to a string offset in C:\xampp\htdocs\wordpress\wp-content\plugins\dk-pdf\includes\mpdf60\classes\cssmgr.php on line 1139 Warning: Illegal string offset 'ID' in C:\xampp\htdocs\wordpress\wp-content\plugins\dk-pdf\includes\mpdf60\classes\cssmgr.php on line 1190 Warning: Illegal string offset 'LANG' in C:\xampp\htdocs\wordpress\wp-content\plugins\dk-pdf\includes\mpdf60\classes\cssmgr.php on line 1190 Warning: A non-numeric value encountered in C:\xampp\htdocs\wordpress\wp-content\plugins\dk-pdf\includes\mpdf60\mpdf.php on line 31965 Warning: count(): Parameter must be an array or an object that implements Countable in C:\xampp\htdocs\wordpress\wp-content\plugins\dk-pdf\includes\mpdf60\classes\otl.php on line 5377 Warning: Illegal string offset 'ID' in C:\xampp\htdocs\wordpress\wp-content\plugins\dk-pdf\includes\mpdf60\classes\cssmgr.php on line 1136 Warning: Cannot assign an empty string to a string offset in C:\xampp\htdocs\wordpress\wp-content\plugins\dk-pdf\includes\mpdf60\classes\cssmgr.php on line 1136 Warning: Illegal string offset 'LANG' in C:\xampp\htdocs\wordpress\wp-content\plugins\dk-pdf\includes\mpdf60\classes\cssmgr.php on line 1139 Warning: Cannot assign an empty string to a string offset in C:\xampp\htdocs\wordpress\wp-content\plugins\dk-pdf\includes\mpdf60\classes\cssmgr.php on line 1139 Warning: Illegal string offset 'ID' in C:\xampp\htdocs\wordpress\wp-content\plugins\dk-pdf\includes\mpdf60\classes\cssmgr.php on line 1190 Warning: Illegal string offset 'LANG' in C:\xampp\htdocs\wordpress\wp-content\plugins\dk-pdf\includes\mpdf60\classes\cssmgr.php on line 1190 Warning: Illegal string offset 'ID' in C:\xampp\htdocs\wordpress\wp-content\plugins\dk-pdf\includes\mpdf60\classes\cssmgr.php on line 1136 Warning: Cannot assign an empty string to a string offset in C:\xampp\htdocs\wordpress\wp-content\plugins\dk-pdf\includes\mpdf60\classes\cssmgr.php on line 1136 Warning: Illegal string offset 'LANG' in C:\xampp\htdocs\wordpress\wp-content\plugins\dk-pdf\includes\mpdf60\classes\cssmgr.php on line 1139 Warning: Cannot assign an empty string to a string offset in C:\xampp\htdocs\wordpress\wp-content\plugins\dk-pdf\includes\mpdf60\classes\cssmgr.php on line 1139 Warning: Illegal string offset 'ID' in C:\xampp\htdocs\wordpress\wp-content\plugins\dk-pdf\includes\mpdf60\classes\cssmgr.php on line 1190 Warning: Illegal string offset 'LANG' in C:\xampp\htdocs\wordpress\wp-content\plugins\dk-pdf\includes\mpdf60\classes\cssmgr.php on line 1190 Warning: Cannot modify header information - headers already sent by (output started at C:\xampp\htdocs\wordpress\wp-content\plugins\dk-pdf\includes\mpdf60\classes\cssmgr.php:1139) in C:\xampp\htdocs\wordpress\wp-content\plugins\dk-pdf\includes\mpdf60\mpdf.php on line 8314 Warning: Cannot modify header information - headers already sent by (output started at C:\xampp\htdocs\wordpress\wp-content\plugins\dk-pdf\includes\mpdf60\classes\cssmgr.php:1139) in C:\xampp\htdocs\wordpress\wp-content\plugins\dk-pdf\includes\mpdf60\mpdf.php on line 1706 mPDF error: Some data has already been output to browser, can't send PDF file ``` Viewing 2 replies - 1 through 2 (of 2 total) * [huegelkind](https://wordpress.org/support/users/mpzimmer/) * (@mpzimmer) * [8 years, 2 months ago](https://wordpress.org/support/topic/mpdf-error-3/#post-10049357) * Howdy, folks, * same here: Warning: Illegal string offset ‘LANG’ in /var/www/k6688-1/htdocs/ blogtogether/spk0/wordpress/wp-content/plugins/dk-pdf/includes/mpdf60/classes/ cssmgr.php on line 1190 * Warning: Cannot modify header information – headers already sent by (output started at /var/www/k6688-1/htdocs/blogtogether/spk0/wordpress/wp-content/plugins/dk- pdf/includes/mpdf60/classes/cssmgr.php:1136) in /var/www/k6688-1/htdocs/blogtogether/ spk0/wordpress/wp-content/plugins/dk-pdf/includes/mpdf60/mpdf.php on line 8297 * Warning: Cannot modify header information – headers already sent by (output started at /var/www/k6688-1/htdocs/blogtogether/spk0/wordpress/wp-content/plugins/dk- pdf/includes/mpdf60/classes/cssmgr.php:1136) in /var/www/k6688-1/htdocs/blogtogether/ spk0/wordpress/wp-content/plugins/dk-pdf/includes/mpdf60/mpdf.php on line 1706 mPDF error: Some data has already been output to browser, can’t send PDF file * [huegelkind](https://wordpress.org/support/users/mpzimmer/) * (@mpzimmer) * [8 years, 2 months ago](https://wordpress.org/support/topic/mpdf-error-3/#post-10050783) * The problem is an incompatibility of mPDF with PHP 7.2. Switch back to PHP 7.0.27 or older and enjoy a beautifully running plugin. Viewing 2 replies - 1 through 2 (of 2 total) The topic ‘mPDF Error’ is closed to new replies. * ![](https://ps.w.org/dk-pdf/assets/icon-256x256.png?rev=3396282) * [DK PDF - WordPress PDF Generator](https://wordpress.org/plugins/dk-pdf/) * [Support Threads](https://wordpress.org/support/plugin/dk-pdf/) * [Active Topics](https://wordpress.org/support/plugin/dk-pdf/active/) * [Unresolved Topics](https://wordpress.org/support/plugin/dk-pdf/unresolved/) * [Reviews](https://wordpress.org/support/plugin/dk-pdf/reviews/) * 2 replies * 2 participants * Last reply from: [huegelkind](https://wordpress.org/support/users/mpzimmer/) * Last activity: [8 years, 2 months ago](https://wordpress.org/support/topic/mpdf-error-3/#post-10050783) * Status: resolved