SSO Troubleshooting: 400 Bad Request during service provider-initiated SSO

Error

Upon initiating single sign-on from Foundry, Foundry directs the user to the identity provider page but we get an error before the user can even try to authenticate, for example "The request cannot be fulfilled because the message received does not meet the security requirements of the login service." This is one sample error message from one identity provider product; in your instance you might see a different error message, or no message at all.

Explanation and Resolution

See 404 Page Not Found Error during SP-initiated SSO . 404 errors often have the same root cause as 400 errors.