Note: [New in v10.50] The SignXML functions now do additional checks on the structure of the XML document and check that all required nodes are present before signing. You are strongly recommended to use the XMLOK/ValidateXml functions on your base document before attempting to sign.

Advanced users: In the event that you need to override this strict behaviour to sign a document (that is, you know the node shown as required is really optional) then use the SAT_XML_OVERRIDE_REQD/SignOptions.OverrideReqd option. This is intended as an "emergency" option.