NPE while parsing BPMN process after modifying from RHPAM 7.13.2 web designer

The customer is trying to create a new version of an existing process definition on RHPAM 7.13.2 using the Business Central designer version 7.1.3.2.

They have updated version using below steps:
1) Import bpmn process( concessione-crediti-v2.6.0.bpmn) into business-central(RHPAM 7.13.2) process editor

2) Customer edits the process name, id, version and process description for creating a version 3.2.0.

3) The customer downloads the modified process definition (with no other changes) and used in the springboot project by generating kjar.

But kjar deployment is failing with NPE:

~~~
INFO [org.drools.compiler.kie.builder.impl.KieContainerImpl] (main) // Start creation of KieBase: isp-processlmbp0-concessione-crediti-base
java.lang.NullPointerException
at org.jbpm.bpmn2.xml.BoundaryEventHandler.end(BoundaryEventHandler.java:62)
at org.drools.core.xml.ExtensibleXmlParser.endElement(ExtensibleXmlParser.java:441)
at org.apache.xerces.parsers.AbstractSAXParser.endElement(AbstractSAXParser.java:598)
at org.apache.xerces.impl.XMLNSDocumentScannerImpl.scanEndElement(XMLNSDocumentScannerImpl.java:673)
at org.apache.xerces.impl.XMLDocumentFragmentScannerImpl$FragmentContentDispatcher.dispatch(XMLDocumentFragmentScannerImpl.java:1645)
at org.apache.xerces.impl.XMLDocumentFragmentScannerImpl.scanDocument(XMLDocumentFragmentScannerImpl.java:324)
at org.apache.xerces.parsers.XML11Configuration.parse(XML11Configuration.java:875)
at org.apache.xerces.parsers.XML11Configuration.parse(XML11Configuration.java:798)
at org.apache.xerces.parsers.XMLParser.parse(XMLParser.java:108)
at org.apache.xerces.parsers.AbstractSAXParser.parse(AbstractSAXParser.java:1198)
at org.apache.xerces.jaxp.SAXParserImpl$JAXPSAXParser.parse(SAXParserImpl.java:564)
at org.apache.xerces.jaxp.SAXParserImpl.parse(SAXParserImpl.java:298)
at org.drools.core.xml.ExtensibleXmlParser.read(ExtensibleXmlParser.java:318)
at org.drools.core.xml.ExtensibleXmlParser.read(ExtensibleXmlParser.java:181)
at org.jbpm.compiler.xml.XmlProcessReader.read(XmlProcessReader.java:78)
at org.jbpm.compiler.ProcessBuilderImpl.addProcessFromXml(ProcessBuilderImpl.java:292)
at org.jbpm.assembler.AbstractProcessAssembler.addResourceAfterRules(AbstractProcessAssembler.java:47)
at org.kie.internal.services.KieAssemblersImpl.addResourceAfterRules(KieAssemblersImpl.java:59)
~~~
Customer modified same BPMN file through text editor and renamed it concessione-crediti-v2.7.0.bpmn. Comparing concessione-crediti-v3.2.0.bpmn and concessione-crediti-v2.7.0.bpmn, we see only two bpmn2:boundaryEvent elements in the xml. In version 2.7.0, boundary events have the attribute cancelActivity="true" specified, while in version 3.2.0 web editors omitted these parameter . That is the reason for the NPE.Its not expected to return null by element.getAttributeNode("cancelActivity") when the attribute "cancelActivity" is not specified.