I just started getting this error today from my authorize.net API implementation and it is preventing customers from making to the payment page.

I'm using the authorize.net API SDK.

My return option URLs are formatted as such:

$success_url = "https://" . $_SERVER['HTTP_HOST'] . "/payment/cc_authorizenet_accept_hosted.php?r=$soidhash";
$cancel_url = "https://" . $_SERVER['HTTP_HOST'] . "/payment/cc_authorizenet_accept_hosted.php?r=$coidhash";

Then put into an array of options:

 $payment_options = array(
        'hostedPaymentSecurityOptions'          =>  "{\"captcha\": false}",
        'hostedPaymentStyleOptions'             =>  "{\"bgColor\": \"#C00\"}",
        'hostedPaymentShippingAddressOptions'   =>  "{\"show\": false, \"required\": true}",
        'hostedPaymentBillingAddressOptions'    =>  "{\"show\": false, \"required\": true}",
        'hostedPaymentButtonOptions'            =>  "{\"text\": \"Submit Secure Payment\"}",
        'hostedPaymentOrderOptions'             =>  "{\"show\": true, \"merchantName\": \"Lee Precision, Inc.\"}",
        'hostedPaymentPaymentOptions'           =>  "{\"cardCodeRequired\": true, \"showCreditCard\": true,\"showBankAccount\": false}",
        'hostedPaymentReturnOptions'            =>  "{\"showReceipt\": true,\"url\": \"{$success_url}\", \"urlText\": \"Get Receipt\", \"cancelUrl\": \"{$cancel_url}\", \"cancelUrlText\": \"Cancel/Continue Shopping\"}"
    );

Then options added using API SDK:

   foreach ($payment_options as $k => $v) {
        $aSetting = new AnetAPI\SettingType();
        $aSetting->setSettingName($k);
        $aSetting->setSettingValue($v);
        $request->addToHostedPaymentSettings($aSetting);
    }

This implementation has been working for about two years, and I have not changed any of the code since then, so I'm not sure if their API is having an issue? Status page says everything is working.

Is there a way on authorize.net to review API requests to see what they are receiving from my server?