Internal Server Error 500

Hello,

We get a fatal error / ISE 500 when you try to subscribe for a stock alert (debug below). Unsubscribing goes fine, double subscription gets alerted correctly too. It seems to be a conflict with “WooCommerce PDF Invoices” (https://ww.wp.xz.cn/plugins/woocommerce-pdf-invoices/) because when we disable that, all goes fine but also vice versa: without your plugin, the invoicing plugin goes fine…

Can you help us identify where the issue is to make these 2 plugins work together? Thanks!

Best regards,
Jurgen

[06-Mar-2017 13:37:51 UTC] PHP Notice: Trying to get property of non-object in /home/jilko451/staging/1/wp-content/plugins/woocommerce-pdf-invoices/includes/be-woocommerce-pdf-invoices.php on line 390
[06-Mar-2017 13:37:51 UTC] PHP Fatal error: Uncaught Error: Call to a member function get_total() on null in /home/jilko451/staging/1/wp-content/plugins/woocommerce-pdf-invoices/includes/be-woocommerce-pdf-invoices.php:424
Stack trace:
#0 /home/jilko451/staging/1/wp-includes/class-wp-hook.php(298): BE_WooCommerce_PDF_Invoices->attach_invoice_to_email(Array, ‘stock_alert_adm…’, NULL)
#1 /home/jilko451/staging/1/wp-includes/plugin.php(203): WP_Hook->apply_filters(Array, Array)
#2 /home/jilko451/staging/1/wp-content/plugins/woocommerce/includes/emails/class-wc-email.php(290): apply_filters(‘woocommerce_ema…’, Array, ‘stock_alert_adm…’, NULL)
#3 /home/jilko451/staging/1/wp-content/plugins/woocommerce-product-stock-alert/classes/emails/class-woo-product-stock-alert-admin-email.php(63): WC_Email->get_attachments()
#4 /home/jilko451/staging/1/wp-content/plugins/woocommerce-product-stock-alert/classes/class-woo-product-stock-alert-ajax.php(139): WC_Admin_Email_Stock_Alert->trigger(‘[email protected]’, ‘14322’, ‘jurgen@makemywe…’)
#5 /home/jilko451/staging/ in /home/jilko451/staging/1/wp-content/plugins/woocommerce-pdf-invoices/includes/be-woocommerce-pdf-invoices.php on line 424