Problem
When running the 'Test SAML Login' button at the end of the SAML configuration wizard, you see the following message :
"{"error":{"message":"user not found","statusCode":401,"data":{"usernameNotFound":"username123"}}}"
Note: username123 in the message example is a placeholder for an actual username that appears in the message.
Solution
Make sure NameID is set to the user's email address.
The NameID value in the XML metadata has username instead of email address.