Open Source Document Management System | OpenKM

I have been able to create new roles and then assign users to the roles.
Each time I change a Users role, the user is not able to login and gets an error message, and I have to change them back to AdminUser so they can log in.
I want to be able to create different user groups so that I can restrict access to some folders in the Taxonomy.
Any suggestions / help?

As is explained in wiki and in some forum post, all users must have UserRole ( mandatory ) is a role for connection that must not be propagated to repository because all users have it. It's administrator job to change default okm:root security configuration for it purpose and add there new roles