wif10201: No valid key mapping found for securityToken: 'System.IdentityModel.Tokens.X509SecurityToken' and issuer: 'http://login.eur.army.mil/adfs/services/trust'.

There are might be 2 cases for this error.

1. Get the actual thumbprint from ADFS and put in web.config thumbprint tag
2. mismatch in port number (running application port number and port number which is configured in ADFS)

First option was my issue.  I changed the thumbprint and the issue was resolved.


Source:
http://stackoverflow.com/questions/24304097/no-valid-key-mapping-found-for-securitytoken