Missing argument 2 for wpdb::prepare()

Replace the function is_user_blog_admin() starting at line 106 of the limit-bogs-per-user.php file in the plugin and ending at line 120 with the following code:

function is_user_blog_admin($user_id,$blog_id){
    global $wpdb;

        $meta_key=$wpdb->prefix.$blog_id.'_capabilities';//.."_user_level";
	$role_sql="SELECT user_id,meta_value FROM {$wpdb->usermeta} WHERE meta_key=%s";

        $role=$wpdb->get_results($wpdb->prepare($role_sql, $meta_key),ARRAY_A);
	//clean the role
	$all_user=array_map(array('BPDevLimitBlogsPerUser','serialize_roles'),$role);//we are unserializing the role to make that as an array

	foreach($all_user as $key=>$user_info)
		if($user_info['meta_value']['administrator']==1&&$user_info['user_id']==$user_id)//if the role is admin
			return true;
	return false;
}

I ran into this problem also and had to fix the plugin. I am going to try to contact the plugin developer and get it fixed.