diff --git a/ordernumbers_woocommerce.php b/ordernumbers_woocommerce.php
index 080dd8ca0a27274846f316bd5937670c0ac7d6eb..ad6b6c797fb9b2120135903575ed40a58e019360 100644
--- a/ordernumbers_woocommerce.php
+++ b/ordernumbers_woocommerce.php
@@ -364,6 +364,8 @@ class OpenToolsOrdernumbers extends OpenToolsOrdernumbersBasic {
 		add_action ('wpo_wcpdf_process_template_order', array($this, 'thirdparty_wpo_wcpdf_create_number'), 10, 2);
 		// Disable the invoice number-related controls in the config of the other plugin
 		add_action ('woocommerce_page_wpo_wcpdf_options_page', array($this, 'thirdparty_wpo_wcpdf_remove_options'));
+		// If this plugin is enabled, but invoice numbers are not, display an information message and a link to the config
+		add_action ('woocommerce_page_wpo_wcpdf_options_page', array($this, 'thirdparty_wpo_wcpdf_configuration_link'));
 	}
 	 
 	/**
@@ -412,6 +414,19 @@ class OpenToolsOrdernumbers extends OpenToolsOrdernumbersBasic {
 		}
 	}
 
+	/**
+	 * If this plugin is installed, but not configured for invoice numbers, 
+	 * Display an information message about this plugin and a link to its config.
+	 */
+	function thirdparty_wpo_wcpdf_configuration_link() {
+		global $wp_settings_fields;
+		if (!$this->invoicenumbers_activated()) {
+			$wp_settings_fields['wpo_wcpdf_template_settings']['invoice']['display_number']['args']['description'] = '<i>' . sprintf($this->helper->__( 'The Open Tools Ordernumbers plugin is installed, but not configured to create invoice numbers. Configure it <a href="%s">here</a> to create invoice numbers.'), $this->invoicenumbers_config_link()) . '</i>';
+		}
+		return $settings;
+	}
+
+
 
 	/** ************************************************************
 	 *  Support for WooCommerce PDF Invoice (woocommerce-pdf-invoice) by WooThemes
@@ -451,6 +466,19 @@ class OpenToolsOrdernumbers extends OpenToolsOrdernumbersBasic {
 	 
 	protected function thirdparty_wc_delivery_notes_init() {
 		// Patch by OpenTools implements the generic interface, so nothing special needs to be done
+		// Setting use WP Settings API, remove the counter-specific settings
+		add_filter ('wcdn_get_settings_no_section', array($this, 'thirdparty_wc_delivery_notes_configuration_link'));
+	}
+
+	/**
+	 * If this plugin is installed, but not configured for invoice numbers, 
+	 * Display an information message about this plugin and a link to its config.
+	 */
+	function thirdparty_wc_delivery_notes_configuration_link($settings) {
+		if (!$this->invoicenumbers_activated()) {
+			$settings['invoice_options']['desc'] = '<i>' . sprintf($this->helper->__( 'The Open Tools Ordernumbers plugin is installed, but not configured to create invoice numbers. Configure it <a href="%s">here</a> to create invoice numbers.'), $this->invoicenumbers_config_link()) . '</i>';
+		}
+		return $settings;
 	}
 
 // END THIRD-PARTY PLUGIN SUPPORT
diff --git a/ordernumbers_woocommerce_basic.php b/ordernumbers_woocommerce_basic.php
index 90b82e5e1bc837bf5f1db3297227dc69d8bdb6f8..92e1aeb23eb20bdaaadac695b07df3ab24a72b3a 100644
--- a/ordernumbers_woocommerce_basic.php
+++ b/ordernumbers_woocommerce_basic.php
@@ -192,10 +192,10 @@ class OpenToolsOrdernumbersBasic {
 		return (get_option('customize_'.$type, 'no')!='no');
 	}
 	public function ordernumbers_activated($default=false) {
-		return $this->numbers_activated('ordernumber');
+		return $default || $this->numbers_activated('ordernumber');
 	}
 	public function invoicenumbers_activated($default=false) {
-		return $this->numbers_activated('invoice');
+		return $default || $this->numbers_activated('invoice');
 	}
 	
 	public function invoicenumbers_config_link($default=null) {
@@ -480,17 +480,17 @@ class OpenToolsOrdernumbersBasic {
 	/** 
 	 * The generic function to retrieve a particular number
 	 */
-	function get_number($orderid, $order, $type = 'ordernumber') {
-		$stored_number = get_post_meta( $orderid, $this->ordernumber_meta.$type, 'true');
+	function get_number($default, $order, $type = 'ordernumber') {
+		$stored_number = get_post_meta( $order->id, $this->ordernumber_meta.$type, 'true');
 		if ($stored_number == $this->ordernumber_new_placeholder) {
 			// Check whether the order was now really created => create order number now
-			return $this->assign_new_ordernumber($orderid, $order, $type);
+			return $this->assign_new_ordernumber($order->id, $order, $type);
 		} elseif (!empty($stored_number)) {
 			// Order number already exists => simply return it
 			return $stored_number;
 		} else {
 			// No order number was created for this order, so simply use the orderid as default.
-			return $orderid;
+			return $default;
 		}
 	}