Hi, as in the other situations, just reinstalling Hika solves (temporary) the error 500.
The php-fpm/www-error.log indicates the following
PHP Fatal error: Allowed memory size of 134217728 bytes exhausted (tried to allocate 151823148652 bytes) in
.../administrator/components/com_hikashop/helpers/helper.php on line 1418
i.e. the PHP process is requesting more than 128 MB (even 151 GB!!!). That line is the closing line of hikashop_loadTranslationFile, after
$lang = JFactory::getLanguage();
$loadOverrideCB = $loadOverride->bindTo($lang, 'JLanguage');
$loadOverrideCB($path);
it seems a memory problem loading the language override value..... :

: ?