Detailed error messages are returned for most API errors within the response body.
However, clients such as the PHP SDK raise an exception with a very generic message.
For better troubleshooting, fine tune your try/catch blocks to trap the ApiException. It yields more information.
Example:
Catching the ApiException
<?php require_once(__DIR__ . '/SwaggerClient-php/autoload.php'); ultracart\v2\Configuration::getDefaultConfiguration()->setApiKey('x-ultracart-simple-key', 'XXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXX'); $api_instance = new ultracart\v2\api\CustomerApi(); $customer_profile_oid = 1234567; // int | The customer oid to retrieve. try { $result = $api_instance->customerCustomersCustomerProfileOidGet($customer_profile_oid); print_r($result); } catch (\ultracart\v2\ApiException $e) { echo 'Exception when calling CustomerApi->customerCustomersCustomerProfileOidGet: ', $e->getMessage(), PHP_EOL; // THE FOLLOWING LINE PROVIDES DETAILED ERROR INFORMATION print_r($e->getResponseObject()); }