Fatal Error – Pitch Theme

Hi installed the plugin “DZS Zoomsounds” and got this error message when going to the “Zoomsounds” settings tab…
“Fatal error: Call to undefined function get_current_screen() in MyDomain.com/wp-content/themes/pitch/extras/settings/settings.php on line 511”

DZS Zoomsounds works in WP 4.1 and with other themes.

Can you please let me know if you can fix this? I like the Pitch theme.
Thank you!

}

function siteorigin_settings_media_view_strings($strings, $post){
	if(!empty($post)) return $strings;
	$screen = get_current_screen();
	if(empty($screen->id) || $screen->id != 'appearance_page_theme_settings_page') return $strings;
	
	// Remove these strings, to remove the tabs
	// Luckily the JS gracefully handles these being unset
	unset($strings['createNewGallery']);
	unset($strings['createGalleryTitle']);
	unset($strings['insertFromUrlTitle']);
	
	$strings['insertIntoPost'] = __('Set Media File', 'pitch');
	
	return $strings;
}