Getting java error while generating jar file

[dineshdeveloper3]

Exception in thread "main" java.lang.ExceptionInInitializerError
at com.thoughtworks.xstream.XStream.setupConverters(XStream.java:989)
at com.thoughtworks.xstream.XStream.(XStream.java:592)
at com.thoughtworks.xstream.XStream.(XStream.java:514)
at com.thoughtworks.xstream.XStream.(XStream.java:483)
at com.thoughtworks.xstream.XStream.(XStream.java:429)
at com.thoughtworks.xstream.XStream.(XStream.java:382)
at org.apache.jmeter.save.SaveService$XStreamWrapper.(SaveService.java:82)
at org.apache.jmeter.save.SaveService$XStreamWrapper.(SaveService.java:80)
at org.apache.jmeter.save.SaveService.(SaveService.java:113)
at com.loadium.postman2jmx.builder.AbstractJmxFileBuilder.buildJmxFile(AbstractJmxFileBuilder.java:104)
at com.loadium.postman2jmx.builder.JmxFileBuilder.build(JmxFileBuilder.java:10)
at com.loadium.postman2jmx.app.Postman2Jmx.main(Postman2Jmx.java:35)
Caused by: java.lang.reflect.InaccessibleObjectException: Unable to make field private final java.util.Comparator java.util.TreeMap.comparator accessible: module java.base does not "opens java.util" to unnamed module @11e21d0e
at java.base/java.lang.reflect.AccessibleObject.throwInaccessibleObjectException(AccessibleObject.java:387)
at java.base/java.lang.reflect.AccessibleObject.checkCanSetAccessible(AccessibleObject.java:363)
at java.base/java.lang.reflect.AccessibleObject.checkCanSetAccessible(AccessibleObject.java:311)
at java.base/java.lang.reflect.Field.checkCanSetAccessible(Field.java:181)
at java.base/java.lang.reflect.Field.setAccessible(Field.java:175)
at com.thoughtworks.xstream.core.util.Fields.locate(Fields.java:40)
at com.thoughtworks.xstream.converters.collections.TreeMapConverter.(TreeMapConverter.java:50)

[jacobjn86]

Facing the same issue

[skczhans]

I also encountered this problem

[hostersi-czerny-szymon]

Use JDK8 for maven and jar execution.