Creating a platform user with AD alias fails in 4.1 (coming from 3.1)

Hi,

I used to be able to create a user using the following:

EnterpriseService boEnterpriseService = s.GetService("", "InfoStore");

                var boInfoStore = newInfoStore(boEnterpriseService);

                var newBoUserPlugin = boInfoStore.PluginManager.GetPluginInfo("CrystalEnterprise.User");

                var userList = boInfoStore.NewInfoObjectCollection();

                var newBoUser = (User)userList.Add(newBoUserPlugin);

                newBoUser.Title = user;

                newBoUser.Aliases.AddNew("secWinAd:" + user, false);

                boInfoStore.Commit(userList);

Unfortunately, it now fails with this error:

Additional information: Failed to commit objects to server :

Create operation failed.

If I omit the alias creation, the user is created normally, but is not linked to an AD account like I need.

Can I achieve the same in 4.1?