 <p>I know this is a bit late but I had a similar problem and I fixed it by adding an <strong>identity</strong> element to the app.config file for the service's endpoint. Example:</p> <pre><code>&lt;identity&gt; &lt;userPrincipalName value="username@domain" /&gt; &lt;/identity&gt; </code></pre> <p>The for me it worked even with an empty value for <strong>userPrincipalName</strong>:</p> <pre><code>&lt;identity&gt; &lt;userPrincipalName value="" /&gt; &lt;/identity&gt; </code></pre> <p>Full endpoint element:</p> <pre><code>&lt;endpoint address="net.tcp://localhost:9876/my-service/tcp" ... &gt; &lt;identity&gt; &lt;userPrincipalName value="" /&gt; &lt;/identity&gt; &lt;/endpoint&gt; </code></pre>