XF 2.2 setting user secondary groups

[RisteDimitrievski]

InvalidArgumentException: Attempted to convert integer to comma-separated list [secondary_group_ids] in src\XF\Mvc\Entity\Entity.php at line 759

$group = $this->filter('group','int');
$em = $this->em()->find('myaddon:entity',$userid);
if($action == "add"){
    $em->secondary_group_ids = $group;
    $em->save();
}

Anybody?

 

[RisteDimitrievski]

I've fixed my problem myself.

the secondary group ids should be in array.