IllegalArgumentException is thrown when trying to iterator over the system registry.

Below is some sample code to reproduce this exception.

SecureRegistry systemRegistry = SharedRegistry.systemRegistry();
systemRegistry.putIfAbsent("lock", SharedLock.create());

Iterator<Entry> e = systemRegistry.iterator();
while (e.hasNext()) {
    Entry ent = e.next();
    System.out.println("ENTRY: " + ent.key() + " " + ent.type());
}

java.lang.IllegalArgumentException: Not a valid Uid string representation: "lock"
        at sun.shared.ResourceID.<init>(ResourceID.java:118)
        at sun.shared.InProcessRegistry.iterator(InProcessRegistry.java:110)
        at com.sun.shared.registry.SecureRegistry.iterator(SecureRegistry.java:175)