diff --git a/htdocs/core/class/commonobject.class.php b/htdocs/core/class/commonobject.class.php
index f8bbcd97511..6d49abf9902 100644
--- a/htdocs/core/class/commonobject.class.php
+++ b/htdocs/core/class/commonobject.class.php
@@ -8203,6 +8203,17 @@ abstract class CommonObject
 
 				if (!empty($classpath)) {
 					dol_include_once($InfoFieldList[1]);
+
+					if ($classname && !class_exists($classname)) {
+						// from V19 of Dolibarr, In some cases link use element instead of class, example project_task
+						// TODO use newObjectByElement() introduce in V20 by PR #30036 for better errors management
+						$element_prop = getElementProperties($classname);
+						if ($element_prop) {
+							$classname = $element_prop['classname'];
+						}
+					}
+
+
 					if ($classname && class_exists($classname)) {
 						$object = new $classname($this->db);
 						if ($object->element === 'product') {	// Special case for product because default valut of fetch are wrong