BusinessManager: Update item_path_list in Business Mangager only when manager is already set

product/ERP5/Document/BusinessManager.py

@@ -743,7 +743,8 @@ class BusinessItem(XMLObject):
       # Update the Business Manager with the path list everytime after editing
       # item_path
       manager = self.getFollowUpValue()
-
+      # Check if the manager has already been set or not
+      if manager:
         # Copy the path list for Business Manager and update it with new path
         item_path_list = manager.getItemPathList()[:]
         old_item_path = self._v_modified_property_dict.get('item_path')