This is a regression in JDK9.
Due to a change in DynamicProxyManager caused by warning cleanup (JDK-JDK-8156586) when a proxy is removed from the ProxyCache we usually get a java.util.ConcurrentModificationException.
We are returning (from getProxyList()) the cached List of proxys instead of a clone of it.
fix is trivial:
         List<Proxy> dup = new ArrayList<Proxy>();
- dup = pInfo;
+ dup.addAll(pInfo);
         return dup;