variantes = amount must be greater than zero

array(11) {
  ["requestEnvelope"]=>
  array(1) {
    ["errorLanguage"]=>
    string(5) "en_US"
  }
  ["actionType"]=>
  string(3) "PAY"
  ["currencyCode"]=>
  string(3) "EUR"
  ["receiverList"]=>
  array(1) {
    [0]=>
    array(2) {
      ["email"]=>
      string(34) "contact-facilitator@email.com"
      ["amount"]=>
      float(0)
    }
  }
  ["feePayer"]=>
  string(12) "EACHRECEIVER"
  ["trackingId"]=>
  string(17) "319#383995b9220e7"
  ["cancelUrl"]=>
  string(109) "https://www.impress-3d.com/index.php?option=com_hikashop&ctrl=order&task=cancel_order&order_id=319&Itemid=224"
  ["returnUrl"]=>
  string(109) "https://www.impress-3d.com/index.php?option=com_hikashop&ctrl=checkout&task=after_end&order_id=319&Itemid=224"
  ["ipnNotificationUrl"]=>
  string(158) "https://www.impress-3d.com/index.php?option=com_hikashop&ctrl=checkout&task=notify¬if_payment=paypaladaptive&order_id=319&tmpl=component&lang=fr&Itemid=224"
  ["reverseAllParallelPaymentsOnError"]=>
  string(4) "true"
  ["clientDetails"]=>
  array(3) {
    ["applicationId"]=>
    string(8) "HikaShop"
    ["ipAddress"]=>
    string(14) "86.000.000.000"
    ["customerId"]=>
    string(2) "87"
  }
}

array(12) {
  ["responseEnvelope.timestamp"]=>
  string(35) "2014-05-28T13%3A19%3A02.340-07%3A00"
  ["responseEnvelope.ack"]=>
  string(7) "Failure"
  ["responseEnvelope.correlationId"]=>
  string(13) "7ff11252c321b"
  ["responseEnvelope.build"]=>
  string(8) "10902368"
  ["error(0).errorId"]=>
  string(6) "580022"
  ["error(0).domain"]=>
  string(8) "PLATFORM"
  ["error(0).subdomain"]=>
  string(11) "Application"
  ["error(0).severity"]=>
  string(5) "Error"
  ["error(0).category"]=>
  string(11) "Application"
  ["error(0).message"]=>
  string(61) "Invalid+request+parameter%3A+amount+must+be+greater+than+zero"
  ["error(0).parameter(0)"]=>
  string(6) "amount"
  ["error(0).parameter(1)"]=>
  string(1) "0"
}