Description of problem:

Having a DRL defining a time window, when updating an event using 

        FactHandle handle = entryPoint.insert(event);

        TestEvent event2 = new TestEvent("testEvent2");
        entryPoint.update(handle, event2);

a CCE is thrown:

java.lang.ClassCastException: org.drools.core.reteoo.WindowNode cannot be cast to org.drools.core.reteoo.BetaNode
	at org.drools.core.reteoo.WindowNode.modifyObject(WindowNode.java:262)

Version-Release number of selected component (if applicable):

Drools 6.0.0-SNAPSHOT
Drools 6.0.0.CR1

This worked in 6.0.0.Beta3.

How reproducible:

Please run the attached reproducer test.

Actual results:

CCE is thrown.

Expected results:

The test passes.