title: ID4175: The issuer of the security token was not recognized by the IssuerNameRegistry
body: <p>I am trying to implement a Simple STS web site alongside my MVC application in a development environment. I was able to get this working properly on my local machine. I would navigate to my MVC app, kicked out to the STS web application, I login, then am redirected back to my MVC app. This is not using AFDS by the way. </p>
  
  <p>When I migrated this to my Development environment, I see similar activity but I get the error below when I login. I have checked about 20 times that my thumbprint in the MVC app is the exact same as the cert. </p>
  
  <p>(The login is working fine as I don't get redirected until the authentication succeeds.) </p>
  
  <p>Any guesses?</p>
  
  <p>Error message I recieve:</p>
  
  <blockquote>
    <p>ID4175: The issuer of the security token was not recognized by the IssuerNameRegistry. To accept security tokens from this issuer, configure the IssuerNameRegistry to return a valid name for this issuer</p>
  </blockquote>
  
  <p>web.config from STS website:</p>
  
  <pre><code>&lt;appSettings&gt;
  &lt;add key="IssuerName" value="STSTestCert"/&gt;
  &lt;add key="SigningCertificateName" value="CN=STSTestCert"/&gt;
  &lt;add key="EncryptingCertificateName" value=""/&gt;
    &lt;/appSettings&gt;
  </code></pre>
  
  <p>web.config from MVC application:</p>
  
  <pre><code>&lt;microsoft.identityModel&gt;
  &lt;service&gt;
    &lt;audienceUris&gt;
      &lt;add value="http://localhost/" /&gt;
    &lt;/audienceUris&gt;
    &lt;federatedAuthentication&gt;
      &lt;wsFederation passiveRedirectEnabled="true" issuer="http://localhost:57543/mySTS/" realm="http://localhost/" requireHttps="false" /&gt;
      &lt;cookieHandler requireSsl="false" /&gt;
    &lt;/federatedAuthentication&gt;
    &lt;applicationService&gt;
      &lt;claimTypeRequired&gt;
        &lt;!--Following are the claims offered by STS 'http://localhost:57543/mySTS/'. Add or uncomment claims that you require by your application and then update the federation metadata of this application.--&gt;
        &lt;claimType type="http://schemas.xmlsoap.org/ws/2005/05/identity/claims/name" optional="true" /&gt;
        &lt;claimType type="http://schemas.microsoft.com/ws/2008/06/identity/claims/role" optional="true" /&gt;
      &lt;/claimTypeRequired&gt;
    &lt;/applicationService&gt;
    &lt;issuerNameRegistry type="Microsoft.IdentityModel.Tokens.ConfigurationBasedIssuerNameRegistry, Microsoft.IdentityModel, Version=3.5.0.0, Culture=neutral, PublicKeyToken=31bf3856ad364e35"&gt;
          &lt;trustedIssuers&gt;
        &lt;add thumbprint="‎11111" name="http://localhost:57543/mySTS/" /&gt;
          &lt;/trustedIssuers&gt;
        &lt;/issuerNameRegistry&gt;
      &lt;/service&gt;
    &lt;/microsoft.identityModel&gt;
  </code></pre>