diff --git a/PROMS/ReferencedObjects/LibSource/RODBInterface/VlnXml.cs b/PROMS/ReferencedObjects/LibSource/RODBInterface/VlnXml.cs
index 307b59b3..dfdf6210 100644
--- a/PROMS/ReferencedObjects/LibSource/RODBInterface/VlnXml.cs
+++ b/PROMS/ReferencedObjects/LibSource/RODBInterface/VlnXml.cs
@@ -723,7 +723,8 @@ namespace RODBInterface
 				{
 					XmlNode radNode = elmnode.FirstChild;
 					string radNodeName = radNode.Name;
-					while (radNode != null && !radNodeName.StartsWith(inusename))
+					//B2021-146 added a null reference check of the next sibling
+					while (radNode != null && radNode.NextSibling != null && !radNodeName.StartsWith(inusename))
 					{
 						radNode = radNode.NextSibling;
 						radNodeName = radNode.Name;