diff --git a/ChangeLog b/ChangeLog
index 07fa52ed00f..cf79e783b35 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -261,6 +261,7 @@ Following changes may create regressions for some external modules, but were nec
 * You must use "$objectoffield" to manipulate the current object inside the formulare of computed custom extrafields instead of $obj/$object.
 * Making a global search is sending the parameter using always the name search_all (instead of sometimes sall and search_all)
 * The property $url_last_version must be public if defined into module descriptor files;
+* Filters in class field definitions must be a Dolibarr filter syntax string.
 
 ***** ChangeLog for 16.0.5 compared to 16.0.4 *****
 
diff --git a/htdocs/compta/facture/card.php b/htdocs/compta/facture/card.php
index 8f65df86da7..be552526e1f 100644
--- a/htdocs/compta/facture/card.php
+++ b/htdocs/compta/facture/card.php
@@ -3901,7 +3901,7 @@ if ($action == 'create') {
 		print $objectsrc->getNomUrl(1);
 		// We check if Origin document (id and type is known) has already at least one invoice attached to it
 		$objectsrc->fetchObjectLinked($originid, $origin, '', 'facture');
-		if (is_array($objectsrc->linkedObjects['facture']) && count($objectsrc->linkedObjects['facture']) >= 1) {
+		if (isset($objectsrc->linkedObjects['facture']) && is_array($objectsrc->linkedObjects['facture']) && count($objectsrc->linkedObjects['facture']) >= 1) {
 			setEventMessages('WarningBillExist', null, 'warnings');
 			echo ' - '.$langs->trans('LatestRelatedBill').' '.end($objectsrc->linkedObjects['facture'])->getNomUrl(1);
 		}
diff --git a/htdocs/knowledgemanagement/knowledgerecord_list.php b/htdocs/knowledgemanagement/knowledgerecord_list.php
index cafb5776cf7..706f103a13d 100644
--- a/htdocs/knowledgemanagement/knowledgerecord_list.php
+++ b/htdocs/knowledgemanagement/knowledgerecord_list.php
@@ -1,6 +1,7 @@
 <?php
-/* Copyright (C) 2007-2017 Laurent Destailleur  <eldy@users.sourceforge.net>
- * Copyright (C) 2021       Frédéric France         <frederic.france@netlogic.fr>
+/* Copyright (C) 2007-2017	Laurent Destailleur		<eldy@users.sourceforge.net>
+ * Copyright (C) 2021		Frédéric France			<frederic.france@netlogic.fr>
+ * Copyright (C) 2023		Anthony Berton			<anthony.berton@bb2a.fr>
  *
  * This program is free software; you can redistribute it and/or modify
  * it under the terms of the GNU General Public License as published by
@@ -293,7 +294,7 @@ if (!empty($searchCategoryKnowledgemanagementList)) {
 		if (intval($searchCategoryKnowledgemanagement) == -2) {
 			$searchCategoryKnowledgemanagementSqlList[] = "NOT EXISTS (SELECT ck.fk_knowledgemanagement FROM ".MAIN_DB_PREFIX."categorie_knowledgemanagement as ck WHERE t.rowid = ck.fk_knowledgemanagement)";
 		} elseif (intval($searchCategoryKnowledgemanagement) > 0) {
-			if ($searchCategoryKnowledgemanagementOperator == 0) {
+			if (empty($searchCategoryKnowledgemanagementOperator)) {
 				$searchCategoryKnowledgemanagementSqlList[] = " EXISTS (SELECT ck.fk_knowledgemanagement FROM ".MAIN_DB_PREFIX."categorie_knowledgemanagement as ck WHERE t.rowid = ck.fk_knowledgemanagement AND ck.fk_categorie = ".((int) $searchCategoryKnowledgemanagement).")";
 			} else {
 				$listofcategoryid .= ($listofcategoryid ? ', ' : '') .((int) $searchCategoryKnowledgemanagement);