Hi,
Please check that your language file is not broken.
The text "X_ITEM_IN_STOCK" is a translation key which should be translated in your language file and can be override in your override file. If you modified the language file and there is an error, some translations might not be loaded correctly and should appear as broken.
Regards,
Jerome - Obsidev.com
HikaMarket & HikaSerial developer / HikaShop core dev team.
Also helping the HikaShop support team when having some time or couldn't sleep.
By the way, do not send me private message, use the "contact us" form instead.