Title: 500 Error Pdf Not Loading
Last modified: July 26, 2017

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# 500 Error Pdf Not Loading

 *  Resolved [torontotodd1](https://wordpress.org/support/users/torontotodd1/)
 * (@torontotodd1)
 * [8 years, 9 months ago](https://wordpress.org/support/topic/500-error-pdf-not-loading/)
 * Hi, I’m getting a 500 error when attempting to print an invoice. In debug mode
   I’m getting this error.
 * Fatal error: Call to undefined function Dompdf\mb_internal_encoding() in /home/
   foodiecards/public_html/wp-content/plugins/woocommerce-pdf-invoices-packing-slips/
   vendor/dompdf/dompdf/src/Dompdf.php on line 274
 * Help is appreciated, thanks!

Viewing 2 replies - 1 through 2 (of 2 total)

 *  Plugin Contributor [Ewout](https://wordpress.org/support/users/pomegranate/)
 * (@pomegranate)
 * [8 years, 9 months ago](https://wordpress.org/support/topic/500-error-pdf-not-loading/#post-9352096)
 * Hello Todd,
    Can you check the Status tab of the PDF Invoice settings and see
   if ‘MBString extension’ is flagged red or orange? If so, this means your PHP 
   installation is missing an important library. Your host should be able to help
   with this, it’s a very common library that is enabled on most hosts.
 * Let me know if MBString was actually enabled already, in that case I will further
   investigate the issue for you.
 *  Thread Starter [torontotodd1](https://wordpress.org/support/users/torontotodd1/)
 * (@torontotodd1)
 * [8 years, 9 months ago](https://wordpress.org/support/topic/500-error-pdf-not-loading/#post-9354027)
 * Perfect, that worked. Thank you for your quick response.
    -Todd

Viewing 2 replies - 1 through 2 (of 2 total)

The topic ‘500 Error Pdf Not Loading’ is closed to new replies.

 * ![](https://ps.w.org/woocommerce-pdf-invoices-packing-slips/assets/icon-256x256.
   png?rev=2189942)
 * [PDF Invoices & Packing Slips for WooCommerce](https://wordpress.org/plugins/woocommerce-pdf-invoices-packing-slips/)
 * [Frequently Asked Questions](https://wordpress.org/plugins/woocommerce-pdf-invoices-packing-slips/#faq)
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 * 2 replies
 * 2 participants
 * Last reply from: [torontotodd1](https://wordpress.org/support/users/torontotodd1/)
 * Last activity: [8 years, 9 months ago](https://wordpress.org/support/topic/500-error-pdf-not-loading/#post-9354027)
 * Status: resolved