Quickbook web connector , sendRequestXML throws Object reference not set to an instance of an object error

Question

I am integrating Quickbook Desktop with my web app using the Quickbook web connector. Authentication works but when the web connector recieves response for sendRequestXML, it fails with this error.

0240128.17:13:40 UTC    : QBWebConnector.SOAPWebService.do_sendRequestXML() : qbNationality="US"
20240128.17:13:40 UTC   : QBWebConnector.SOAPWebService.do_sendRequestXML() : qbXMLMajorVers="16"
20240128.17:13:40 UTC   : QBWebConnector.SOAPWebService.do_sendRequestXML() : qbXMLMinorVers="0"
20240128.17:13:40 UTC   : QBWebConnector.SOAPWebService.do_sendRequestXML() : Received from sendRequestXML() following parameter:
20240128.17:13:40 UTC   : QBWebConnector.SOAPWebService.do_sendRequestXML() : strRequestXML =
20240128.17:13:40 UTC   : QBWebConnector.SOAPWebService.do_sendRequestXML() : QBWC1041: SendRequestXML failed.
Error message: Object reference not set to an instance of an object.
More info:
StackTrace =    at QBWebConnector.Logger.log(String method, String logText)
   at QBWebConnector.WebService.log(String method, String logText)
   at QBWebConnector.WebService.do_sendRequestXML(Int32 x, String wcTicket, String HCPResponseXML, String cfn, String qbNationality, Int32 qbXMLMajorVers, Int32 qbXMLMinorVers, Boolean& timeout)
Source = QBWCCommon

this is what my response of sendRequestXML looks like:

<?xml version='1.0' encoding='utf-8'?><soap:Envelope xmlns:soap='http://schemas.xmlsoap.org/soap/envelope/' xmlns:xsi='http://www.w3.org/2001/XMLSchema-instance
' xmlns:xsd='http://www.w3.org/2001/XMLSchema'><soap:Body><sendRequestXMLResponse xmlns='http://developer.intuit.com'><sendRequestXMLResult>&lt;?qbxml version="
13.0"?&gt;&lt;QBXML&gt;&lt;QBXMLMsgsRq onError="stopOnError"&gt;&lt;EmployeeQueryRq requestID="c1" /&gt;&lt;/QBXMLMsgsRq&gt;&lt;/QBXML&gt;</sendRequestXMLResult></sendRequestXMLResponse></soap:Body></soap:Envelope>

I have tried returning the XML in various diferrent formats. i am hoping to fix the xml response that i am returning so that sendRequestXML call succeeds.