Issue in Format of First Name and Last Name of User

[Devanshu_Malik]

By default the first name of user has dot ‘.’ in it and last name is null.
But when user tries to change the user name then there is restrictions like ’ first/last name can only contain alphabets’ , which means that it can’t have any special character nor it can be left as blank/null which contradicts the initial format of first and last name.