Table of contents
"Extra content at the end of the document."
An XML document is only allowed to have one root element in order to be well-formed. Make sure that the tag your document starts with is not closed until the end of the document.
According to ISO 20022 payments initiation message standard the document root element is <Document>.
A rough example of the structure of an ISO 20022 payments message:
<Document> <!-- Root element started -->
<GrpHdr>Group Header elements here</GrpHdr>
Payment Information elements here
<CdtTrfTxInf>Credit Transfer Transaction Information elements here</CdtTrfTxInf>
</Document> <!-- Root element closed -->