Custom filter modification casuses white screen

Hello, Developers!

I have an issue with filters.

We needed to add a custom filter to our Accounts module and make it default. ( In fact, we wanted to list only our "active" accounts as default. The base issue was that users when to create a new opportunity they were able to pick Inactive Accounts, and this caused some misunderstandings and other errors. The difference between "active" and "inactive" account was only a custom fields dropdown value called "Status".)

I found a workaround and was perfect. We had the new filter called "Active Accounts". But during parameterizing the new filter I just made a mistake: the create operator was set to false. This caused that users lost the ability in Accounts module to create they own filters, the Create option disappeared. 

So I edited again the file, and set create value from "false" to "true", but after Repair, I got a blank screen aka "white screen". The sugar logs are not saying anything nor the apache log. 

I provide the filter code for sure:

<?php
$module_name = "Accounts";
$viewdefs[$module_name]['base']['filter']['aktiv'] = array(
    'create'               => true,
    'filters'              => array(
        array(
            'id'                => 'aktiv',
            'name'              => 'LBL_AKTIV',
            'filter_definition' => array(
                array(
                    'szervezet_statusza_c' => 'aktiv',
                ),
            ),
            'editable'          => true,
        ),
    ),
);

We using the Sugar CRM Enterprise, 7.8 version.

Thank You for Your help!

Regards, 

Arpad Sabo