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
Had the wrong thumbprint for the certificate that was being used (the Certificate
used to encrypt the soap messages is the only one that you need the thumbprint for.)
Best Solution-> Implement the Thinktecture’s TestIssuerNameRegistry, which overrides the default ConfigurationBasedIssuerNameRegistry so that you don’t need to explicitly reference the thumbprint