To check users' login credentials, my script makes a call to a REST API. I have confirmed that the API is working (the script can pass login credentials and receive a response as to whether the credentials are correct). But after successfully authenticating, I get an NPE: ``` java.lang.NullPointerException: null at org.gluu.oxauth.service.AuthenticationService.configureSessionUser(AuthenticationService.java:609) ~[classes/:?] at org.gluu.oxauth.service.AuthenticationService$Proxy$_$$_WeldClientProxy.configureSessionUser(Unknown Source) ~[classes/:?] at org.gluu.oxauth.auth.Authenticator.userAuthenticationInteractive(Authenticator.java:434) ~[classes/:?] at org.gluu.oxauth.auth.Authenticator.authenticateImpl(Authenticator.java:205) ~[classes/:?] at org.gluu.oxauth.auth.Authenticator.authenticate(Authenticator.java:128) ~[classes/:?] at jdk.internal.reflect.GeneratedMethodAccessor348.invoke(Unknown Source) ~[?:?] at jdk.internal.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43) ~[?:?] ``` My script's `authenticate` method: ``` def authenticate(self, configurationAttributes, requestParameters, step): identity = CdiUtil.bean(Identity) credentials = identity.getCredentials() sessionIdService = CdiUtil.bean(SessionIdService) print 'Authenticating User %s' % (credentials.username) cred_json = json.dumps({ 'login': credentials.username, 'password': credentials.password }) print 'Connecting to authserver' try: response_raw = requests.post('http://localhost:2345/authenticate', data=cred_json, headers={'Content-type': 'application/json'}) except Exception as e: print e return False print 'Parsing response' try: response = json.loads(response_raw.text) except Exception as e: print e return False status = response['status'] if status != 'OK': return False return True ``` Other than a few irrelevant lines I've omitted, this is the entire `authenticate()` method. I installed the LDAP backend when I installed Gluu, but the user I've authenticated does not exist in LDAP. I'm hoping it doesn't have to exist in LDAP... What am I doing wrong?