Title: WordPress has found a problem with PostNL plugin
Last modified: May 13, 2023

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# WordPress has found a problem with PostNL plugin

 *  [haakplein](https://wordpress.org/support/users/haakplein/)
 * (@haakplein)
 * [3 years, 1 month ago](https://wordpress.org/support/topic/wordpress-has-found-a-problem-with-postnl-plugin/)
 * **I still can’t print any lavels (see prvious topic, which has remained unanswered
   for 2 months… WordPress itself is a bit more proactive and has sent me the below
   information, hopefully someone can pick up the error details and fix the issue
   now.**
   WordPress heeft een ingebouwde functie die herkent wanneer een plugin 
   of thema een fatale fout veroorzaakt op je site en die je op de hoogte stelt 
   met deze automatische e-mail.In dit geval heeft WordPress een probleem gevonden
   met één van je plugins: PostNL for WooCommerce.Bezoek eerst je site ([https://haakplein.com/home/](https://haakplein.com/home/))
   en kijk of er zichtbare problemen zijn. Bezoek daarna de pagina waar de fout 
   was gevonden ([https://haakplein.com/home/home/wp-admin/edit.php?s=&post_status=all&post_type=shop_order&_wpnonce=9c491755a7&_wp_http_referer=%2Fhome%2Fwp-admin%2Fedit.php%3Fpost_type%3Dshop_order&action=postnl-create-label&m=0&_customer_user=&paged=1&post%5B%5D=7704&action2=postnl-create-label&postnl_letterbox=yes&postnl_num_labels=1&postnl_label_nonce=aac82b51dd](https://haakplein.com/home/home/wp-admin/edit.php?s=&post_status=all&post_type=shop_order&_wpnonce=9c491755a7&_wp_http_referer=%2Fhome%2Fwp-admin%2Fedit.php%3Fpost_type%3Dshop_order&action=postnl-create-label&m=0&_customer_user=&paged=1&post%5B%5D=7704&action2=postnl-create-label&postnl_letterbox=yes&postnl_num_labels=1&postnl_label_nonce=aac82b51dd))
   en kijk of er zichtbare problemen zijn.Als je hulp nodig hebt met dit probleem,
   kan je gevraagd worden om de volgende informatie:WordPress versie 6.2Actief thema:
   Hello Elementor (versie 2.7.1)Huidige plugin: PostNL for WooCommerce (versie 
   5.2.0)PHP versie 7.4.27Foutdetails===========Een fout van het type E_ERROR werd
   veroorzaakt op regelnummer 65 van het bestand /home/vhosts/[haakplein.com/httpdocs/home/wp-content/plugins/woo-postnl/src/Library/CustomizedPDFMerger.php](http://haakplein.com/httpdocs/home/wp-content/plugins/woo-postnl/src/Library/CustomizedPDFMerger.php).
   Foutmelding: Uncaught Exception: No PDFs to merge. in /home/vhosts/[haakplein.com/httpdocs/home/wp-content/plugins/woo-postnl/src/Library/CustomizedPDFMerger.php:65](http://haakplein.com/httpdocs/home/wp-content/plugins/woo-postnl/src/Library/CustomizedPDFMerger.php:65)
   Stack trace:#0 /home/vhosts/[haakplein.com/httpdocs/home/wp-content/plugins/woo-postnl/src/Order/Base.php](http://haakplein.com/httpdocs/home/wp-content/plugins/woo-postnl/src/Order/Base.php)(
   672): PostNLWooCommerce\Library\CustomizedPDFMerger->merge(‘file’, ‘/home/vhosts/
   ha…’)#1 /home/vhosts/[haakplein.com/httpdocs/home/wp-content/plugins/woo-postnl/src/Order/Bulk.php](http://haakplein.com/httpdocs/home/wp-content/plugins/woo-postnl/src/Order/Bulk.php)(
   131): PostNLWooCommerce\Order\Base->merge_labels(Array, ‘postnl-bulk-1.p…’)#2/
   home/vhosts/[haakplein.com/httpdocs/home/wp-content/plugins/woo-postnl/src/Order/Bulk.php](http://haakplein.com/httpdocs/home/wp-content/plugins/woo-postnl/src/Order/Bulk.php)(
   91): PostNLWooCommerce\Order\Bulk->merge_bulk_labels(Array)#3 /home/vhosts/[haakplein.com/httpdocs/home/wp-includes/class-wp-hook.php](http://haakplein.com/httpdocs/home/wp-includes/class-wp-hook.php)(
   308): PostNLWooCommerce\Order\Bulk->process_order_bulk_actions(‘/home/wp-admin/…’,‘
   postnl-create-l…’, Array)#4 /home/vhosts/[haakplein.com/httpdocs/home/wp-includes/plugin.php](http://haakplein.com/httpdocs/home/wp-includes/plugin.php)(
   205): WP_Hook->apply_filters(‘/home/wp-admin/…’, Array)#5 /home/vhosts/[haakplein.com/httpdocs/ho](http://haakplein.com/httpdocs/ho)

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

 *  [Reüel](https://wordpress.org/support/users/pronamic_reuel/)
 * (@pronamic_reuel)
 * [2 years, 11 months ago](https://wordpress.org/support/topic/wordpress-has-found-a-problem-with-postnl-plugin/#post-16864806)
 * I hope you were able to resolve the issue in the mean time, but I wanted to add
   that I came across the same issue today and in our case this was caused by an
   invalid API key in the settings (**WooCommerce > Settings > Shipping methods 
   > PostNL > Production API Key**). The correct API Key can be found in **Mijn 
   PostNL → Account**.
 * I found the following error message with the logging setting enabled:
 * > API Key is not valid or is expired / revoked.
 *  Thread Starter [haakplein](https://wordpress.org/support/users/haakplein/)
 * (@haakplein)
 * [2 years, 11 months ago](https://wordpress.org/support/topic/wordpress-has-found-a-problem-with-postnl-plugin/#post-16866249)
 * Nope that was not it. API key on our account is the same as on our PostNL account
   and it has not expired.

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

The topic ‘WordPress has found a problem with PostNL plugin’ is closed to new replies.

 * ![](https://ps.w.org/woo-postnl/assets/icon-256x256.png?rev=1807921)
 * [PostNL for WooCommerce](https://wordpress.org/plugins/woo-postnl/)
 * [Frequently Asked Questions](https://wordpress.org/plugins/woo-postnl/#faq)
 * [Support Threads](https://wordpress.org/support/plugin/woo-postnl/)
 * [Active Topics](https://wordpress.org/support/plugin/woo-postnl/active/)
 * [Unresolved Topics](https://wordpress.org/support/plugin/woo-postnl/unresolved/)
 * [Reviews](https://wordpress.org/support/plugin/woo-postnl/reviews/)

 * 2 replies
 * 2 participants
 * Last reply from: [haakplein](https://wordpress.org/support/users/haakplein/)
 * Last activity: [2 years, 11 months ago](https://wordpress.org/support/topic/wordpress-has-found-a-problem-with-postnl-plugin/#post-16866249)
 * Status: not resolved