CDI specification does not allow proxying a class with non-private final
methods. The java.util.Hashtable class has a
non-private final method added to the class in later versions
of Java, so a CDI application that previously worked may break
when updating the Java level.

This issue was logged in CDI-527.
OpenWebBeans fixed this via the jira (
Can Weld fix this in the 2.3 or 2.2 trunk?

Emily Jiang