In /catalog/includes/languages/english/product_info.php on line ~22

*** Find ***

?>


*** Before that, add ***

// BOF: Display tax info
define('TEXT_INCLUDING_TAXES', 'W/ tax');
define('TEXT_EXCLUDING_TAXES', 'W/o tax');
// EOF: Display tax info


you must add
define('TEXT_INCLUDING_TAX', 'W/ tax');
define('TEXT_EXCLUDING_TAX', 'W/o tax');

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