I was trying to setup my own ADFS Server and my web app talking to it, but stumbled upon this error on my web app.
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
A plain simple Bing search lead me to this blog post
. I am posting the solution for the benefit of all.
The error really means that there is a mismatch between the issuer certificate details mentioned in the web.config's <Microsoft.identityModel /> section. So back to your ADFS server grab that thumbprint of the certificate and update it in the web.config of your app.
Version=126.96.36.199, Culture=neutral, PublicKeyToken=31bf3856ad364e35">
<certificateValidation certificateValidationMode="None" />
There are more details about other exceptions and how to fix them here