A parse error is generated when saving the Shop Parameters or Affiliate Program if there is a string in the config.inc.php that contains escaped double quotes, i.e. \"
AShop solves issues with quotes and double quotes by using their equivalent html entities instead. Remove the escaped double quotes from config.inc.php and then enter them as normal double quotes from the Store Configuration pages. This will save them in a safe format in your config.inc.php file, which will not cause any parse errors.