When using the modify operator in Drools I am getting a java.lang.ClassCastException: org.adcb.finance.ResponseFact cannot be cast to org.drools.core.common.InternalFactHandle.

This seems to happen in rules that contain Arrays & using the in/not in operator on them. I have other rules using the matches regex expression and I dont get this issue.

This is a critical issue for us as we're using the RulesExecutionService in 6.4.0 to extend the KIE Execution service and are due to go live very soon so there is no chance of rolling back to 6.3.x without some heavy rework.