Status Detail: 5068 when using sagePay - aes

Question

I am trying to use SagePay. I have an account and I would like to use Server Integration.
The error I get is Status Detail: 5068 : The encryption method is not supported by this protocol version.
I'm trying to create a simple 'pay now' button, as described in the documents. The code samples provided by sage don't appear to work.
Can someone please let me know why the code below doesnt work? thanks
<?php
require_once ('lib/SagePay.php');
$sagePay = new SagePay();
$sagePay->setCurrency('BG');
$sagePay->setAmount('100');
$sagePay->setDescription('Lorem ipsum');
$sagePay->setBillingSurname('Mustermann');
$sagePay->setBillingFirstnames('Max');
$sagePay->setBillingCity('Cologne');
$sagePay->setBillingPostCode('50650');
$sagePay->setBillingAddress1('Bahnhofstr. 1');
$sagePay->setBillingCountry('de');
$sagePay->setDeliverySameAsBilling();
/* Example of using BasketXML */
$xml = new DOMDocument();
$basketNode = $xml->createElement("basket");
$itemNode = $xml->createElement("item");
$descriptionNode = $xml->createElement( 'description' );
$descriptionNode->nodeValue = 'First Item Description';
$itemNode -> appendChild($descriptionNode);
$quantityNode = $xml->createElement('quantity');
$quantityNode->nodeValue = '1';
$itemNode -> appendChild($quantityNode);
$unitNetAmountNode = $xml->createElement('unitNetAmount');
$unitNetAmountNode->nodeValue = '90.00';
$itemNode -> appendChild($unitNetAmountNode);
$unitTaxAmountNode = $xml->createElement('unitTaxAmount');
$unitTaxAmountNode->nodeValue = '10.00';
$itemNode -> appendChild($unitTaxAmountNode);
$unitGrossAmountNode = $xml->createElement('unitGrossAmount');
$unitGrossAmountNode->nodeValue = '100.00';
$itemNode -> appendChild($unitGrossAmountNode);
$totalGrossAmountNode = $xml->createElement('totalGrossAmount');
$totalGrossAmountNode->nodeValue = '100.00';
$itemNode -> appendChild($totalGrossAmountNode);
$basketNode->appendChild( $itemNode );
$xml->appendChild( $basketNode );
$sagePay->setBasketXML($xml->saveHTML());
$sagePay->setSuccessURL('https://website.co.uk/page.html');
$sagePay->setFailureURL('https://website.co.uk/page.html');
?>
<form method="POST" id="SagePayForm" action="https://test.sagepay.com/gateway/service/vspform-register.vsp">
<input type="hidden" name="VPSProtocol" value= "3.00">
<input type="hidden" name="TxType" value= "PAYMENT">
<input type="hidden" name="Vendor" value= "vendorname here">
<input type="hidden" name="Crypt" value= "<?php echo $sagePay->getCrypt(); ?>">
<input type="submit" value="continue to SagePay">
</form>

Answer 1

Couple of things to check:
Ensure you are using AES encryption on the Crypt field
When sending the crypt over to Sage Pay, make sure it is prefixed '#'
Make sure you are not Base64 encoding the string after you have AES encrypted it (the protocol documents are a little misleading in this regard)
[update]: 4. You are actually using the Form integration method...

Answer 2

Thanks for the help on this.
It was a problem with the encryption method. The code that eventually worked for me was this one:
https://github.com/tolzhabayev/sagepayForm-php/blob/master/lib/SagePay.php
And my form button is like this:
<form method="POST" id="SagePayForm" action="https://test.sagepay.com/gateway/service/vspform-register.vsp">
<input type="hidden" name="VPSProtocol" value= "3.00">
<input type="hidden" name="TxType" value= "PAYMENT">
<input type="hidden" name="Vendor" value= "vendornamehere">
<input type="hidden" name="Crypt" value= "<?php echo $sagePay->getCrypt(); ?>">
<input type="submit" value="continue to SagePay">
</form>