[@robin-w Moderator 8 years ago]

ok, I presume you meant this code

//code to add tutor role 
 
function add_new_roles( $bbp_roles )
{
    /* Add a role called tutor */
    $bbp_roles['bbp_tutor'] = array(
        'name' => 'Tutor',
        'capabilities' => custom_capabilities( 'bbp_tutor' )
        );
 
    return $bbp_roles;
}
 
add_filter( 'bbp_get_dynamic_roles', 'add_new_roles', 1 );
 
function add_role_caps_filter( $caps, $role )
{
    /* Only filter for roles we are interested in! */
    if( $role == 'bbp_tutor' )
        $caps = custom_capabilities( $role );
 
    return $caps;
}
 
add_filter( 'bbp_get_caps_for_role', 'add_role_caps_filter', 10, 2 );
 
function custom_capabilities( $role )
{
    switch ( $role )
    {
 
        /* Capabilities for 'tutor' role */
        case 'bbp_tutor':
            return array(
                // Primary caps
                'spectate'              => true,
                'participate'           => true,
                'moderate'              => false,
                'throttle'              => false,
                'view_trash'            => false,
 
                // Forum caps
                'publish_forums'        => false,
                'edit_forums'           => false,
                'edit_others_forums'    => false,
                'delete_forums'         => false,
                'delete_others_forums'  => false,
                'read_private_forums'   => true,
                'read_hidden_forums'    => false,
 
                // Topic caps
                'publish_topics'        => true,
                'edit_topics'           => true,
                'edit_others_topics'    => false,
                'delete_topics'         => false,
                'delete_others_topics'  => false,
                'read_private_topics'   => true,
 
                // Reply caps
                'publish_replies'       => true,
                'edit_replies'          => true,
                'edit_others_replies'   => false,
                'delete_replies'        => false,
                'delete_others_replies' => false,
                'read_private_replies'  => true,
 
                // Topic tag caps
                'manage_topic_tags'     => false,
                'edit_topic_tags'       => false,
                'delete_topic_tags'     => false,
                'assign_topic_tags'     => true,
            );
 
            break;
 
        default :
            return $role;
    }
}

so with that code loaded to my site, if I go to

dashboard>users>all users and edit a user, I can change them to the tutor role, and back again and it saves.

Can you confirm you are using the above code, and that it does not save if you perform the above ?