title: Error: Validation input failed The server cannot handle directory requests
body: <p>We had a application which needs user credentials for installation. Till some time back it was working fine. But all of a sudden it was throwing &quot;<strong>Error: Validation input failed  The server cannot handle directory requests.</strong> &quot; If I try the installation in a particular corporate domain  of 100 times with domain credentials, 4 times I was successful and 96 times I failed. But same installation is working fine with local domain setup(Not corporate) and some other corporate domain's also. Any hint please help us. Thanks in advance.</p>
  <pre><code>if (group.IsDomain())
          {
              if (user.GetAuthorizationGroups().Any(userGroup =&gt; userGroup.Name == &quot;Administrators&quot;))
              {
                  this.MessageLog.Information(&quot;domain user is part of local Administrators '{0}'.&quot;, user.Name);
                  return true;
              }
              else
              {
               
  </code></pre>