FULL PRODUCT VERSION :
java version "1.8.0_161"
Java(TM) SE Runtime Environment (build 1.8.0_161-b12)
Java HotSpot(TM) 64-Bit Server VM (build 25.161-b12, mixed mode)


ADDITIONAL OS VERSION INFORMATION :
Microsoft Windows [Version 10.0.16299.192]

A DESCRIPTION OF THE PROBLEM :
While using SOAP handler to modify the header (https://gist.github.com/sivaprasadreddy/2555700 or https://www.ibm.com/support/knowledgecenter/SSFPJS_8.0.0/com.ibm.wbpm.wid.integ.doc/topics/rjaxwshandlercogsoaphdr.html) call to getEnvelope() failes with

com.sun.xml.internal.messaging.saaj.soap.SOAPDocumentImpl createEntityReference
SAAJ0543

This happens only if the content of the soap messages contains new lines. Eg.

class A {
String text;
}

If this class is sent with a single line string it works but if this string contains a new line - so multiple lines - the getEnvelope() failes.

REGRESSION. Last worked in version 8u151


REPRODUCIBILITY :
This bug can be reproduced always.