issue about registering user

hi when i run my android project i can register 1 user but when i try to rgister another user i get error "objectId is a reserved system property and is not allowed when registering a user." the fault code is 3039 but im never do anything to object id, hres my code
BackendlessUser user = new BackendlessUser();
user.setEmail(editTextEmail.getText().toString());
user.setPassword(editTextPassword.getText().toString());
Backendless.UserService.register(user, new BackendlessCallback<BackendlessUser>() {
@Override
public void handleResponse(BackendlessUser response) {

Log.v(“success”,“Register success”);
}
@Override
public void handleFault(BackendlessFault fault){
Log.v(“fail”,fault.getMessage());
}
});

Hi Kurnia,

In your code I only see how you register one user. Where does the registration of another user occur?

In case you’re trying to call “register” again with the same “user” object the error is expected, because you have already registered this user object (even though you might have changed the email and password values).