Sonata Admin integration with FOSuser

Question

I'm using Symfony 2.1 for a project. i use FOSUser Bundle for managing users & customize it for my application. now i want to use SonataAdmin Bundle for administration usage. it works fine for normal entities (I can do the usual CRUD things) but for users, I get a user list & link in the dashboard but when I follow create new or click to edit, I get a 500 server error saying

"Class does not exist"

I don't want to use SonataUser Bundle because i did lot's of customization on my userBundle & i don't want to loose them..

any idea?any example? Thanks for your helps :)

related codes:

in config.yml :

services:
    sonata.admin.user:
        class: Acme\AdminBundle\Admin\UserAdmin
        arguments: [null, Acme\GeneralModelBundle\Entity\User, SonataAdminBundle:CRUD]
        calls:
          - [setUserManager, ["@fos_user.user_manager"]]
        tags:
          - {name: sonata.admin , manager_type: orm, group: Users, label: User}

Answer 1

finally i found the problem!! in Sonata Admin documentation it had an example for UserAdmin which i used,in this example it adds groups in configureFormFields function which is not enabled by default in FOSUser Bundle.. so when i comment that line every thing goes well!! :))

protected function configureFormFields(FormMapper $formMapper)
{
    $formMapper
        ->with('General')
            ->add('username')
            ->add('email')
            ->add('plainPassword', 'text')
        ->end()
      /******************************************************************* 
          ->with('Groups')
          ->add('groups', 'sonata_type_model', array('required' => false))
        ->end() 
       ******************************************************************/
        ->with('Management')
            ->add('roles', 'sonata_security_roles', array( 'multiple' => true))
            ->add('locked', null, array('required' => false))
            ->add('expired', null, array('required' => false))
            ->add('enabled', null, array('required' => false))
            ->add('credentialsExpired', null, array('required' => false))
        ->end()
    ;
}