Add User in Manage Users - we get error

1. Click on 'System Administration'>'Advanced Administration'>'Manage Users' - You should see User Management page
2. Click on 'Add User' - You should see Add User page
3. In 'Given' enter "Super" in 'Family Name' enter "Nurse", 'Gender' choose 'Female', In 'User's Password' enter "Nurse321" in 'Confirm Password' enter "Nurse321" and click on 'Save User'
And without choose the 'Roles' we can create Users. When we log out and want to log in user who we created, e.g. in 'Username' enter: "super_nurse", 'Password' enter "Nurse321", click on 'Log in' and in this moment application is crashing. We get message from our browser that error concerns cookies. When we delete cookies from our history then application is working.

To find the bug I would start from looking at https://github.com/openmrs/openmrs-module-referenceapplication/blob/master/omod/src/main/java/org/openmrs/module/referenceapplication/page/controller/LoginPageController.java or somewhere in that module.