I am trying to use okta as IDP for my SAML SSO login.
However, when clicking “Login via okta SAML” on my SP, it generates error like “External authentication returned an invalid message”. When checking the SAML response message from okta, I can see that in the response, there are characters like “+”, which is encoded format of character “+”. I have to manually decode the characters, and then get the correct XML strings of the SAML response.
Any ideas why this is happening?