NullPointerException in NamespacePrefixMapperUtils

Hello Team,
I am using docx4j 3.3.5 to manipulate some documents in my web application project. It is working fine with Java 6 and IBM WAS 7 server.
Recently we migrated to IBM Liberty server with version 19.0.0.1 with java version 1.8 and when I run same application I am seeing below exception.
I tried adding jaxb-impl and updating docx4j version but did not help. Please advise how do I fix this.
(Context) - java.vendor=IBM Corporation
02/19/2019 12:55:44 INFO (Context) - java.version=1.8.0_191
02/19/2019 15:36:00 DEBUG (NamespacePrefixMapperUtils) - attempting to setProperty on marshaller com.ibm.xml.xlxp2.jaxb.marshal.MarshallerProxy
02/19/2019 15:36:00 ERROR (ContentTypeManager) - java.lang.NullPointerException
java.lang.RuntimeException: java.lang.NullPointerException
at org.docx4j.XmlUtils.marshaltoString(XmlUtils.java:832)
at org.docx4j.openpackaging.contenttype.ContentTypeManager.parseContentTypesFile(ContentTypeManager.java:746)
at org.docx4j.openpackaging.io3.Load3.get(Load3.java:134)
at org.docx4j.openpackaging.packages.OpcPackage.load(OpcPackage.java:462)
at org.docx4j.openpackaging.packages.OpcPackage.load(OpcPackage.java:379)
at org.docx4j.openpackaging.packages.OpcPackage.load(OpcPackage.java:345)
at org.docx4j.openpackaging.packages.OpcPackage.load(OpcPackage.java:310)
at org.docx4j.openpackaging.packages.WordprocessingMLPackage.load(WordprocessingMLPackage.java:180)
...
...
Caused by: java.lang.NullPointerException
at org.docx4j.jaxb.NamespacePrefixMapperUtils.setProperty(NamespacePrefixMapperUtils.java:197)
at org.docx4j.XmlUtils.marshaltoString(XmlUtils.java:783)
In WAS 7 server, it is workine fine with logs
Context) - java.vendor=IBM Corporation
02/20/2019 05:18:20 INFO (Context) - java.version=1.6.0
....
02/20/2019 05:18:32 DEBUG (XmlUtils) - name: {http://schemas.openxmlformats.org/package/2006/content-types}Types
02/20/2019 05:18:32 DEBUG (NamespacePrefixMapperUtils) - attempting to setProperty on marshaller com.ibm.xml.xlxp2.jaxb.marshal.MarshallerProxy
02/20/2019 05:18:32 DEBUG (NamespacePrefixMapperUtils) - attempting to setProperty: com.sun.xml.INTERNAL.bind.namespacePrefixMapper
02/20/2019 05:18:32 DEBUG (ContentTypeManager) - Registered png
I am using docx4j 3.3.5 to manipulate some documents in my web application project. It is working fine with Java 6 and IBM WAS 7 server.
Recently we migrated to IBM Liberty server with version 19.0.0.1 with java version 1.8 and when I run same application I am seeing below exception.
I tried adding jaxb-impl and updating docx4j version but did not help. Please advise how do I fix this.
(Context) - java.vendor=IBM Corporation
02/19/2019 12:55:44 INFO (Context) - java.version=1.8.0_191
02/19/2019 15:36:00 DEBUG (NamespacePrefixMapperUtils) - attempting to setProperty on marshaller com.ibm.xml.xlxp2.jaxb.marshal.MarshallerProxy
02/19/2019 15:36:00 ERROR (ContentTypeManager) - java.lang.NullPointerException
java.lang.RuntimeException: java.lang.NullPointerException
at org.docx4j.XmlUtils.marshaltoString(XmlUtils.java:832)
at org.docx4j.openpackaging.contenttype.ContentTypeManager.parseContentTypesFile(ContentTypeManager.java:746)
at org.docx4j.openpackaging.io3.Load3.get(Load3.java:134)
at org.docx4j.openpackaging.packages.OpcPackage.load(OpcPackage.java:462)
at org.docx4j.openpackaging.packages.OpcPackage.load(OpcPackage.java:379)
at org.docx4j.openpackaging.packages.OpcPackage.load(OpcPackage.java:345)
at org.docx4j.openpackaging.packages.OpcPackage.load(OpcPackage.java:310)
at org.docx4j.openpackaging.packages.WordprocessingMLPackage.load(WordprocessingMLPackage.java:180)
...
...
Caused by: java.lang.NullPointerException
at org.docx4j.jaxb.NamespacePrefixMapperUtils.setProperty(NamespacePrefixMapperUtils.java:197)
at org.docx4j.XmlUtils.marshaltoString(XmlUtils.java:783)
In WAS 7 server, it is workine fine with logs
Context) - java.vendor=IBM Corporation
02/20/2019 05:18:20 INFO (Context) - java.version=1.6.0
....
02/20/2019 05:18:32 DEBUG (XmlUtils) - name: {http://schemas.openxmlformats.org/package/2006/content-types}Types
02/20/2019 05:18:32 DEBUG (NamespacePrefixMapperUtils) - attempting to setProperty on marshaller com.ibm.xml.xlxp2.jaxb.marshal.MarshallerProxy
02/20/2019 05:18:32 DEBUG (NamespacePrefixMapperUtils) - attempting to setProperty: com.sun.xml.INTERNAL.bind.namespacePrefixMapper
02/20/2019 05:18:32 DEBUG (ContentTypeManager) - Registered png