Fatal error: Call to a member function display() on a non-object in theme_config.php

I have this website that was working perfectly, but today all of the sudden I open it and nothing shows up. So I went and enabled WP_DEBUG and I got this fatal error.

“Fatal error: Call to a member function display() on a non-object in /home/Mywebsite/public_html/wp-content/themes/medica-parent/theme_config/config/theme_config.php on line 12”

I have no Idea what it means. I can’t even access the Website.com/wp-login.php. I even disabled every plugin from the database but that didn’t help.

Can you guys please help me out here. I’m sorry I’m new to WordPress.

Here is the code from that file.

<?php
/**
* Generate theme details
*/
global $wp_version;
if(version_compare('3.3.2',$wp_version,'>=')) {
    $theme_info = get_theme_data(TEMPLATEPATH . '/style.css');
    $cfg['theme_version'] = $theme_info['Version'];
} else {
    $theme_info = wp_get_theme(null, WP_CONTENT_DIR . '/themes/');
    if ( is_child_theme() )
        $cfg['theme_version'] = $theme_info->parent()->display('Version');
    else
        $cfg['theme_version'] = $theme_info->display('Version');
}
$template_info = @get_theme_data(TEMPLATEPATH . '/style.css');

$cfg['theme_version'] = $template_info['Version'];
$cfg['mods_version'] = '2.0.8';
$cfg['theme_name'] = 'Medica';
$cfg['prefix'] = sanitize_title($cfg['theme_name']);
$cfg['author_name'] = 'ThemeFuse';
$cfg['theme_author'] = '<a target="_blank" href="http://themefuse.com">ThemeFuse</a> - ';
$cfg['forum_url'] = 'http://themefuse.com/forum/medica-wp/';
$cfg['manual_url'] = 'http://themefuse.com/wp-docs/medica/';

//$cfg['disabled_extensions'] = array('SLIDER');

$cfg['disabled_extensions'] = array();

$cfg['screen_options']['nav-menus'] = array('add-post','add-post_tag');

$cfg['install_options']['tax'] = array($cfg['prefix'] . '_homepage_category', 'categories_select');
$cfg['install_options']['pos'] = array('posts_select');