Uncaught ValueError

Hi,

I got an e-mail from wordpress saying there is a problem with the plugin Invoices for WooCommerce.
I hope you can help me with this, because it is too technical for me to understand.

This is the message:

Uncaught ValueError: Path cannot be empty in /var/www/nlsunp-pozharevo/wordpress/current/wp-content/plugins/woocommerce-pdf-invoices/includes/abstracts/abstract-document.php:146
Stack trace:
#0 /var/www/nlsunp-pozharevo/wordpress/current/wp-content/plugins/woocommerce-pdf-invoices/includes/abstracts/abstract-document.php(146): file_get_contents()
#1 /var/www/nlsunp-pozharevo/wordpress/current/wp-content/plugins/woocommerce-pdf-invoices/includes/abstracts/abstract-invoice.php(319): BEWPI_Abstract_Document->generate()
#2 /var/www/nlsunp-pozharevo/wordpress/current/wp-content/plugins/woocommerce-pdf-invoices/includes/woocommerce-pdf-invoices.php(567): BEWPI_Abstract_Invoice->generate()
#3 /var/www/nlsunp-pozharevo/wordpress/current/wp-includes/class-wp-hook.php(309): BE_WooCommerce_PDF_Invoices->attach_invoice_to_email()
#4 /var/www/nlsunp-pozharevo/wordpress/current/wp-includes/plugin.php(191): WP_Hook->apply_filters()
#5 /var/www/nlsunp-pozharevo/wordpress/current/wp-content/plugins/woocommerce/includes/emails/class-wc-email.php(434): apply_filters()
#6 /var/www/nlsunp-pozharevo/wordpress/current/wp-content/plugins/woocommerce/includes/emails/class-wc-email-customer-completed-order.php(69): WC_Email->get_attachments()
#7 /var/www/nlsunp-pozharevo/wordpress/current/wp-includes/class-wp-hook.php(307): WC_Email_Customer_Completed_Order->trigger()
#8 /var/www/nlsunp-pozharevo/wordpress/current/wp-includes/class-wp-hook.php(331): WP_Hook->apply_filters()
#9 /var/www/nlsunp-pozharevo/wordpress/current/wp-includes/plugin.php(524): WP_Hook->do_action()
#10 /var/www/nlsunp-pozharevo/wordpress/current/wp-content/plugins/woocommerce/includes/class-wc-emails.php(170): do_action_ref_array()
#11 /var/www/nlsunp-pozharevo/wordpress/current/wp-includes/class-wp-hook.php(307): WC_Emails::send_transactional_email()
#12 /var/www/nlsunp-pozharevo/wordpress/current/wp-includes/class-wp-hook.php(331): WP_Hook->apply_filters()
#13 /var/www/nlsunp-pozharevo/wordpress/current/wp-includes/plugin.php(476): WP_Hook->do_action()
#14 /var/www/nlsunp-pozharevo/wordpress/current/wp-content/plugins/woocommerce/includes/class-wc-order.php(364): do_action()
#15 /var/www/nlsunp-pozharevo/wordpress/current/wp-content/plugins/woocommerce/includes/class-wc-order.php(222): WC_Order->status_transition()
#16 /var/www/nlsunp-pozharevo/wordpress/current/wp-content/plugins/woocommerce/includes/class-wc-order.php(334): WC_Order->save()
#17 /var/www/nlsunp-pozharevo/wordpress/current/wp-content/plugins/woocommerce/includes/admin/list-tables/class-wc-admin-list-table-orders.php(684): WC_Order->update_status()
#18 /var/www/nlsunp-pozharevo/wordpress/current/wp-includes/class-wp-hook.php(307): WC_Admin_List_Table_Orders->handle_bulk_actions()
#19 /var/www/nlsunp-pozharevo/wordpress/current/wp-includes/plugin.php(191): WP_Hook->apply_filters()
#20 /var/www/nlsunp-pozharevo/wordpress/current/wp-admin/edit.php(212): apply_filters()
#21 {main}
thrown

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