Index: Core/Common/src/Core.Common.Gui/Converters/KeyValueExpandableArrayConverter.cs
===================================================================
diff -u -rc4b24c0a4946d7cd20c0fb302aa9c8e30f10afc6 -r6dfb859db2be89f278bf8eca8a4c0b0e15111b41
--- Core/Common/src/Core.Common.Gui/Converters/KeyValueExpandableArrayConverter.cs	(.../KeyValueExpandableArrayConverter.cs)	(revision c4b24c0a4946d7cd20c0fb302aa9c8e30f10afc6)
+++ Core/Common/src/Core.Common.Gui/Converters/KeyValueExpandableArrayConverter.cs	(.../KeyValueExpandableArrayConverter.cs)	(revision 6dfb859db2be89f278bf8eca8a4c0b0e15111b41)
@@ -47,7 +47,7 @@
 
         public override PropertyDescriptorCollection GetProperties(ITypeDescriptorContext context, object value, Attribute[] attributes)
         {
-            var keyValueAttribute = context?.PropertyDescriptor?.Attributes[typeof(KeyValueElementAttribute)] as KeyValueElementAttribute;
+            var keyValueAttribute = context?.PropertyDescriptor?.Attributes?[typeof(KeyValueElementAttribute)] as KeyValueElementAttribute;
 
             if (keyValueAttribute == null)
             {