plugin does not work

Probably your theme is modifying the headers and thus incompatible with the plugin, you can change the theme or disable the function in your theme that is rendering incompatibility. If you are sure that there are no other plugins that is the most probable cause. Some themes are messing with the wordpress emails and thus making these issues.

• This reply was modified 3 years, 1 month ago by Georgi Bakalski.

I changed the theme to the wordpress defaults and nothing changed.
I disabled woocommerce emails and nothing has changed, I don’t think so and the themes

Are you self hosting the site or is it on a commercial hosting server? We have a testing environment with 5.9.1 and the plugin is working flawlessly. So maybe you have some other problem?

commercial hosting server, I will create a test environment to see.

after changing the theme the error changed

Warning: Cannot modify header information - headers already sent by (output started at /home/*******/public_html/wp-includes/plugin.php:957) in /home/*******/public_html/wp-includes/functions.php on line 6821

Warning: Cannot modify header information - headers already sent by (output started at /home/*******/public_html/wp-includes/plugin.php:957) in /home/*******/public_html/wp-admin/includes/misc.php on line 1310

Fatal error: Uncaught Error: Undefined constant "‘woocommerce_email_order_meta’" in /home/*******/public_html/wp-content/plugins/woo-instant-notifications/admin/class-wcnotifications-instance.php:279 Stack trace: #0 /home/*******/public_html/wp-content/plugins/woo-instant-notifications/admin/class-wcnotifications-instance.php(250): WCNotifications_Instance->woocommerce_email_order_meta() #1 /home/*******/public_html/wp-content/plugins/woo-instant-notifications/admin/class-wcnotifications-instance.php(106): WCNotifications_Instance->convert_template() #2 /home/*******/public_html/wp-includes/class-wp-hook.php(309): WCNotifications_Instance->trigger(3287) #3 /home/*******/public_html/wp-includes/class-wp-hook.php(331): WP_Hook->apply_filters('', Array) #4 /home/*******/public_html/wp-includes/plugin.php(522): WP_Hook->do_action(Array) #5 /home/*******/public_html/wp-content/plugins/woocommerce/includes/class-wc-emails.php(170): do_action_ref_array('woocommerce_ord...', Array) #6 /home/*******/public_html/wp-includes/class-wp-hook.php(307): WC_Emails::send_transactional_email(Array, Object(Automattic\WooCommerce\Admin\Overrides\Order)) #7 /home/*******/public_html/wp-includes/class-wp-hook.php(331): WP_Hook->apply_filters('', Array) #8 /home/*******/public_html/wp-includes/plugin.php(474): WP_Hook->do_action(Array) #9 /home/*******/public_html/wp-content/plugins/woocommerce/includes/class-wc-order.php(373): do_action('woocommerce_ord...', 3287, Object(Automattic\WooCommerce\Admin\Overrides\Order)) #10 /home/*******/public_html/wp-content/plugins/woocommerce/includes/class-wc-order.php(222): WC_Order->status_transition() #11 /home/*******/public_html/wp-content/plugins/woocommerce/includes/admin/meta-boxes/class-wc-meta-box-order-data.php(635): WC_Order->save() #12 /home/*******/public_html/wp-includes/class-wp-hook.php(309): WC_Meta_Box_Order_Data::save(3287) #13 /home/*******/public_html/wp-includes/class-wp-hook.php(331): WP_Hook->apply_filters(NULL, Array) #14 /home/*******/public_html/wp-includes/plugin.php(474): WP_Hook->do_action(Array) #15 /home/*******/public_html/wp-content/plugins/woocommerce/includes/admin/class-wc-admin-meta-boxes.php(222): do_action('woocommerce_pro...', 3287, Object(WP_Post)) #16 /home/*******/public_html/wp-includes/class-wp-hook.php(309): WC_Admin_Meta_Boxes->save_meta_boxes(3287, Object(WP_Post)) #17 /home/*******/public_html/wp-includes/class-wp-hook.php(331): WP_Hook->apply_filters('', Array) #18 /home/*******/public_html/wp-includes/plugin.php(474): WP_Hook->do_action(Array) #19 /home/*******/public_html/wp-includes/post.php(4687): do_action('save_post', 3287, Object(WP_Post), true) #20 /home/*******/public_html/wp-includes/post.php(4789): wp_insert_post(Array, false, true) #21 /home/*******/public_html/wp-admin/includes/post.php(426): wp_update_post(Array) #22 /home/*******/public_html/wp-admin/post.php(227): edit_post() #23 {main} thrown in /home/*******/public_html/wp-content/plugins/woo-instant-notifications/admin/class-wcnotifications-instance.php on line 279

• This reply was modified 3 years ago by nicado.

Again, it is something specific (non-standard) to your installation.You can try Edit /wp-content/plugins/woo-instant-notifications/admin/class-wcnotifications-instance.php

and delete the line that contains :

$this->placeholders[‘{woocommerce_email_order_meta}’] = $this->woocommerce_email_order_meta();

I guess, that the suggestion solved youe issues?

sorted out a lot thanks

I wonder what resolved the issue for you, because there is another user with similar issue and your resolution may help him as well.