[SOLVED] OC update Undefined Variable in heading title

OC Version:2.3.0.2
Theme: Lexus_store

I have been working on updating our OC from 1.5.6.4 to 2.3.0.2 I am only a basic coder and have been having many issues with the conversion. We are unable to go to the newest version of OC because are mods are not supported past this point.
I am just trying to basically duplicate our current site (omnicubed.com), our working site is (omnicubed.com/dev)
In my process I somehow broke the product header.

(old site what it should look like) http://omnicubed.com/index.php?route=pr ... uct_id=236
(new development site what it currently looks like) http://omnicubed.com/dev/index.php?rout ... uct_id=236

I have tracked down the issue to this section of code in my file system/storage/modification/catalog/view/theme/lexus_store/template/product/product_detail_hitech.tpl

But for some reason when i check the equivalent section on my old site the code is the same. Please help!

<h1 class="heading_title"><span style="display: none;"><?php echo $heading_title; ?></span></h1>
<div class="product-info">
<div class="row">
<?php require( ThemeControlHelper::getLayoutPath( 'common/detail/'.$mode.'.tpl' ) ); ?>

<div class="col-xs-12 col-sm-<?php echo $cols[1]; ?> col-md-<?php echo $cols[1]; ?> col-lg-<?php echo $cols[1]; ?>">
<h1 class="title-product"><?php echo $heading_title; ?></h1>

The heading_title Variable is not defined, for what reason ever, in that Custom Theme,
wich probably contains some ../controller/... - files & functions as well.
... /dev/catalog/view/theme/lexus_store/template/common/detail/default.tpl
and this .../detail/default.tpl is also no default OC Code.
You should therefore better get in contact with the Theme Seller, there is something
missing somewhere, no-one else would be able to know about.
Good Luck!
Ernie