[rules-users] Consequence Exception with too many events

I am new to Drools (Expert and Fusion) and have been reading through the materials over the last few days. After going through some of the tutorial code I wrote a very quick and dirty to perform a base assessment of the speed of Fusion / Expert. My code is below. The strange thing I'm currently receiving is, if I insert 100k events the test completes successfully, if I insert 150k events, I receive a ConsequenceException caused by an NPE. Being new to Drools I must be doing something wrong, can anyone please provide some guidance? (Main function) Counter cc = new Counter (); session.insert (cc); for (int i = 0; i < 150000; i++) { entryPoint01.insert (new MyEvent ()); } (Counter Class) public class Counter { private long total = 0; // get / set total public void addValue (int val) { total += val; } } (MyEvent Class) public class MyEvent { private int value = 1; // get / set value } (DRL file) declare MyEvent @role (event) @expires (1s) end rule "Count the rules" when $ev : MyEvent () from entry-point entryPoint01 $pc : Counter () then $cc.addValue ($ev.getValue ()); end