ISSUE:
When creating a new user, you have entered in all the required fields (First Name, Last Name, Initials, Security Group, User Type, Region, Default Warehouse, Default Language) including the login name and password, and you click on Save & Exit and nothing appears to happen with no error message.
SOLUTION:
Usually this is because you have entered the same login name and password as another user.
Each AyaNova user needs to have an unique login name and password.