user gets Warning You can't access the private section of this site when they try to log in

Hi

This is what I have done before I encountered "Warning
You can't access the private section of this site." when I tried to log in as one of users.
( This is a test user )

1. Create various user groups copying the core "-Registered" via JOOMLA > Users > Group
2. Create various Easysocial profile type, each one of them is assigned to a different permission group.
3. Due to the error, I added "-Registered" to the user, Then I could log in.

I thought other custom user group are copy of the core "-Registered" user group, Permission would be exactly same. Why do you think I have the error?
Is it because "Joomla Global Config > User Manager > New User Registration Group" is remained "-Registered"?

Please advise what I need to modify in order to allow them to login the site?

Many thanks

Hisako