[MPH-191] help:evaluate fails on Java 18 - java.util.Hashtable.table not accessible

**[Ondrej Zizka](https://issues.apache.org/jira/secure/ViewProfile.jspa?name=JIRAUSER297654)** opened **[MPH-191](https://issues.apache.org/jira/browse/MPH-191?redirect=false)** and commented

When running help:evaluate:

```
com.thoughtworks.xstream.converters.reflection.ReflectionConverter[ERROR] message[2] : Unable to make field private transient java.util.Hashtable$Entry[] java.util.Hashtable.table accessible: module java.base does not "opens java.util" to unnamed module @4fc3529

```

```

$ $MVN $MVN_OPTS help:system help:effective-settings help:effective-pom dependency:tree help:evaluate -Dexpression=project.properties -q -DforceStdout[ERROR] Failed to execute goal org.apache.maven.plugins:maven-help-plugin:3.3.0:evaluate (default-cli) on project tracker-service-app: Execution default-cli of goal org.apache.maven.plugins:maven-help-plugin:3.3.0:evaluate failed: No converter available[ERROR] ---- Debugging information ----[ERROR] message : No converter available[ERROR] type : org.apache.maven.plugins.help.AbstractEffectiveMojo$SortedProperties[ERROR] converter : com.thoughtworks.xstream.converters.reflection.SerializableConverter[ERROR] message[1] : Unable to make private void java.util.Hashtable.readObject(java.io.ObjectInputStream) throws java.io.IOException,java.lang.ClassNotFoundException accessible: module java.base does not "opens java.util" to unnamed module @4fc3529[ERROR] converter[1] : com.thoughtworks.xstream.converters.reflection.ReflectionConverter[ERROR] message[2] : Unable to make field private transient java.util.Hashtable$Entry[] java.util.Hashtable.table accessible: module java.base does not "opens java.util" to unnamed module @4fc3529
```

---

**Affects:** 3.3.0

Start by reproducing the help:evaluate command shown in the report on Java 18 and inspect the maven-help-plugin 3.3.0 evaluation path involved in the failure. Done means the command completes without the XStream accessibility error and produces the requested project.properties output.

Written by the indexing model from the issue text.