Cannot create a new Portal User via the Organization API in EPP 5

Issue

I am trying to add a new user to the portal by using the Organization API.Here is our code to create the user:
       userHandlerImpl.createUser(user, true);

which fails with the following error:

INFO  [org.exoplatform.services.organization.idm.UserDAOImpl] (http-127.0.0.1-8180-1) Cannot obtain user: test01; 
org.picketlink.idm.common.exception.IdentityException: IdentityObjectType[USER] not present in the store.
    at org.picketlink.idm.impl.store.hibernate.HibernateIdentityStoreImpl.getHibernateIdentityObjectType(HibernateIdentityStoreImpl.java:2586)
    at org.picketlink.idm.impl.store.hibernate.HibernateIdentityStoreImpl.findIdentityObject(HibernateIdentityStoreImpl.java:659)
    at org.picketlink.idm.impl.repository.WrapperIdentityStoreRepository.findIdentityObject(WrapperIdentityStoreRepository.java:155)
    at org.picketlink.idm.impl.api.session.managers.PersistenceManagerImpl.findUser(PersistenceManagerImpl.java:426)
    at org.exoplatform.services.organization.idm.UserDAOImpl.getPopulatedUser(UserDAOImpl.java:638)
    at org.exoplatform.services.organization.idm.UserDAOImpl.findUserByName(UserDAOImpl.java:283)
    at com.custom.UserManager.createUser()
...
Caused by: org.hibernate.HibernateException: createCriteria is not valid without active transaction
    at org.hibernate.context.ThreadLocalSessionContext$TransactionProtectionWrapper.invoke(ThreadLocalSessionContext.java:338)
    at $Proxy214.createCriteria(Unknown Source)
    at org.picketlink.idm.impl.store.hibernate.HibernateIdentityStoreImpl.getHibernateIdentityObjectType(HibernateIdentityStoreImpl.java:2560)
    ... 40 more