Null value returned in SAML response for attribute causes looping behavior

As stated on the article "SAML use case: Microsoft Azure as Identity Provider" the following fields are required:

If not populated, the authentication will fail and you will find an entry in the log similar to the below:

022-09-12 12:49:08.108 628034488 [http-nio-8080-exec-8] ERROR org.springframework.boot.web.support.ErrorPageFilter - Forwarding to error page from request [/saml/SSO/alias/iriusrisk-sp] due to exception [Validation Error(s) occurred during save():
- Field error in object 'com.iriusrisk.User' on field 'firstName': rejected value [null]; codes [com.iriusrisk.User.firstName.nullable.error.com.iriusrisk.User.firstName,com.iriusrisk.User.firstName.nullable.error.firstName,com.iriusrisk.User.firstName.nullable.error.java.lang.String,com.iriusrisk.User.firstName.nullable.error,user.firstName.nullable.error.com.iriusrisk.User.firstName,user.firstName.nullable.error.firstName,user.firstName.nullable.error.java.lang.String,user.firstName.nullable.error,com.iriusrisk.User.firstName.nullable.com.iriusrisk.User.firstName,com.iriusrisk.User.firstName.nullable.firstName,com.iriusrisk.User.firstName.nullable.java.lang.String,com.iriusrisk.User.firstName.nullable,user.firstName.nullable.com.iriusrisk.User.firstName,user.firstName.nullable.firstName,user.firstName.nullable.java.lang.String,user.firstName.nullable,nullable.com.iriusrisk.User.firstName,nullable.firstName,nullable.java.lang.String,nullable]; arguments [firstName,class com.iriusrisk.User]; default message [Property [{0}] cannot be null]
]
grails.validation.ValidationException: Validation Error(s) occurred during save():
- Field error in object 'com.iriusrisk.User' on field 'firstName': rejected value [null]; codes [com.iriusrisk.User.firstName.nullable.error.com.iriusrisk.User.firstName,com.iriusrisk.User.firstName.nullable.error.firstName,com.iriusrisk.User.firstName.nullable.error.java.lang.String,com.iriusrisk.User.firstName.nullable.error,user.firstName.nullable.error.com.iriusrisk.User.firstName,user.firstName.nullable.error.firstName,user.firstName.nullable.error.java.lang.String,user.firstName.nullable.error,com.iriusrisk.User.firstName.nullable.com.iriusrisk.User.firstName,com.iriusrisk.User.firstName.nullable.firstName,com.iriusrisk.User.firstName.nullable.java.lang.String,com.iriusrisk.User.firstName.nullable,user.firstName.nullable.com.iriusrisk.User.firstName,user.firstName.nullable.firstName,user.firstName.nullable.java.lang.String,user.firstName.nullable,nullable.com.iriusrisk.User.firstName,nullable.firstName,nullable.java.lang.String,nullable]; arguments [firstName,class com.iriusrisk.User]; default message [Property [{0}] cannot be null]

        at sun.reflect.NativeConstructorAccessorImpl.newInstance0(Native Method)

To Resolve:

Ensure that the account field inside the IDP is not Null, once the Null field has been updated to reflect the relevant value the issue should be resolved.