I've attached the patch for no HTTPS bouncers installations.
The error means there is no connection to the vat checking service. The results are cached for 10 minutes by default. So, you can try
clearing the cache and try again.
If problem persists, please try enabling the logging for the VAT checking service. To do that define a constant in config.local.php script e.g. as follows:
PHP Code:
define('XC_VAT_NUMBER_CHECKER_DEBUG', 1);
If you have no config.local.php file, just create a new one in the X-Cart installation directory. The content of the file should be like this:
PHP Code:
<?php define('XC_VAT_NUMBER_CHECKER_DEBUG', 1); ?>
After that check the var/log directory and find the
x-errors_xcisvatappspot-xxxxxx.php file.