Unsupported by lazy loading

Hi,

When i am trying to execute below code i am getting java.lang.RuntimeException: Unsupported by lazy loading.

private Cases case;
User user;
List<Details> cases;
                    if (null != ag.getDetails()) {
                        cases = ag.getDetails();
                    } else {
                        cases = new ArrayList<Details>();
                    }
                    cases.add(case);

                   user.setDetailscases);
                    dataManager.save(user);

I had changed my fetch from fetch = FetchType.LAZY to FetchType.EAGER still i am getting same issue.

Now it is also observed that same code is running properly when project is run in debug mode but when run as normal application it shows lazy loading error

Please provide the source code of your Cases, Details and User entities, and the full stacktrace of the exception.