Class member has value in Watch but throw null reference exception when step over
<pre><code> public class TfsProject : ITfsProject
    {
    private Project m_TfsProject;
    private TswaClientHyperlinkService m_TfsHyperlinkService;

public TfsProject(Project p) //class constructor
        {
            m_TfsProject = p;
            m_TfsHyperlinkService = (TswaClientHyperlinkService)(p.Store.TeamProjectCollection.GetService(typeof(TswaClientHyperlinkService)));

        }

...........................

public WorkItemDescriptor GetDescriptor(int id)
        {
            WorkItemDescriptor workitem= new WorkItemDescriptor();
            workitem.WorkItemId = id;
            workitem.HyperlinkUri = m_TfsHyperlinkService.GetWorkItemEditorUrl(id).AbsoluteUri;
            return workitem;
        }

    ..................
}
</code></pre>

<p>in Watch and QuickWatch  <strong>m_TfsHyperlinkService.GetWorkItemEditorUrl(id).AbsoluteUri</strong> has value, but when i try to assign/return this value throws null reference exception.</p>

<pre><code>var a = m_TfsHyperlinkService; //has value !=null
var b= a.GetWorkItemEditorUrl(id) //has value !=null in Watch but throw null reference exception when step over
</code></pre>