php 7 - FosCommentBundle assetic exception to Symfony3 -

i'm trying use foscommentbundle symfony3.

i complete steps installation documentation of bundle.

i add appkernel infos , created database, updated schemas , added jquery3.

but when try check index.html.twig gives following error.

there no extension able load configuration "assetic" (in c:\xampp\htdocs\blogbundle\app/config\config.yml). looked namespace "assetic", found "framework", "security", "twig", "monolog", "swiftmailer", "doctrine", "sensio_framework_extra", "fos_rest", "fos_comment", "jms_serializer", "debug", "web_profiler", "sensio_distribution", "web_server" in c:\xampp\htdocs\blogbundle\app/config\config.yml (which being imported "c:\xampp\htdocs\blogbundle\app/config/config_dev.yml"). 

my config.yml

fos_comment:     db_driver: orm     class:         model:             comment: appbundle\entity\comment             thread: appbundle\entity\thread  assetic:     bundles: [ "foscommentbundle" ] 

routing.yml

app:     resource: '@appbundle/controller/'     type: annotation  fos_comment_api:     type: rest     resource: "@foscommentbundle/resources/config/routing.yml"     prefix: /api     defaults: { _format: html } 

entities: - comment.php

<?php  namespace appbundle\entity;  use doctrine\orm\mapping orm; use fos\commentbundle\entity\comment basecomment;  /**  * @orm\entity  * @orm\changetrackingpolicy("deferred_explicit")  */ class comment extends basecomment {     /**      * @orm\id      * @orm\column(type="integer")      * @orm\generatedvalue(strategy="auto")      */     protected $id;      /**      * thread of comment      *      * @var thread      * @orm\manytoone(targetentity="appbundle\entity\thread")      */     protected $thread; } 

thread.php

<?php  namespace appbundle\entity;   use doctrine\orm\mapping orm; use fos\commentbundle\entity\thread basethread;  /**  * @orm\entity  * @orm\changetrackingpolicy("deferred_explicit")  */ class thread extends basethread {     /**      * @var string $id      *      * @orm\id      * @orm\column(type="string")      */     protected $id; } 

all have install assetic bundle.

composer requires symfony/assetic-bundle , add registerbundles in appkernel

new symfony\bundle\asseticbundle\asseticbundle(),

and add config.yml

assetic:    debug:          '%kernel.debug%'    use_controller: '%kernel.debug%'    filters:         cssrewrite: ~