System.ArgumentNullException in TransformFixtureXmlResult.SelectSingleNode

[MarcFlynn2]

We get a System.ArgumentNullException in TransformFixtureXmlResult.SelectSingleNode when decoratedNavigator contains namespace prefix and nothing match.

Exemple:
var navigator = result.SelectSingleNode("/ab:Config/ab:Section/ab:Setting");
if (navigator==null)
{ ... }

Stack
System.ArgumentNullException was unhandled by user code
HResult=-2147467261
Message=Value cannot be null.
Parameter name: decoratedNavigator
Source=Be.Stateless.BizTalk.Unit
ParamName=decoratedNavigator
StackTrace:
at Be.Stateless.BizTalk.Xml.XPathNavigatorDecorator..ctor(XPathNavigator decoratedNavigator) in c:\Files\Projects\be.stateless\BizTalk.Factory\src\BizTalk.Unit\Xml\XPathNavigatorDecorator.cs:line 31
at Be.Stateless.BizTalk.Unit.Transform.TransformFixtureXmlResult..ctor(XPathNavigator decoratedNavigator, XmlNamespaceManager xmlNamespaceManager) in c:\Files\Projects\be.stateless\BizTalk.Factory\src\BizTalk.Unit\Unit\Transform\TransformFixtureXmlResult.cs:line 31
at Be.Stateless.BizTalk.Unit.Transform.TransformFixtureXmlResult.CreateXPathNavigatorDecorator(XPathNavigator decoratedNavigator) in c:\Files\Projects\be.stateless\BizTalk.Factory\src\BizTalk.Unit\Unit\Transform\TransformFixtureXmlResult.cs:line 89
at Be.Stateless.BizTalk.Xml.XPathNavigatorDecorator.SelectSingleNode(String xpath, IXmlNamespaceResolver resolver) in c:\Files\Projects\be.stateless\BizTalk.Factory\src\BizTalk.Unit\Xml\XPathNavigatorDecorator.cs:line 226
at Be.Stateless.BizTalk.Unit.Transform.TransformFixtureXmlResult.SelectSingleNode(String xpath) in c:\Files\Projects\be.stateless\BizTalk.Factory\src\BizTalk.Unit\Unit\Transform\TransformFixtureXmlResult.cs:line 80
at ...
InnerException:

Package: BizTalk.Factory 1.0.19308.32846
Namespace: Be.Stateless.BizTalk.Unit.Transform
Class: TransformFixtureXmlResult
Method: SelectSingleNode

Thank you for the support !