Undefined WP_Error::$ID on line 16

I slightly hacked the code.The error is not shown now

function buddypress_login_redirection($redirect_url,$request_url,$user)
{
	global $bp;
	if( $user && is_object( $user ) && is_a( $user, 'WP_User' ) ) {

		$selected_option = get_option('blr_select_redirection');
		if($selected_option == 'one')
		{
			return bp_core_get_user_domain($user->ID).'profile/';
		}
		elseif($selected_option=='two')
		{
			$activity_slug = bp_get_activity_root_slug();
			$redirect_url = $bp->root_domain."/".$activity_slug;
			return $redirect_url;
		}
		else
		{
			$activity_slug = bp_get_activity_root_slug();
			$friends_activity = bp_core_get_user_domain($user->ID).$activity_slug."/friends/";
			return $friends_activity;
		}
    	}
    return $redirect_url;
}

Good Work…