Hi all, I am converting over to Drools 5 and have run into a problem with AccumulateFunction. I changed my classes to implement org.drools.runtime.rule.AccumulateFunction however this causes the ClassCastException below: Caused by: java.lang.ClassCastException: au.com.promedicus.rules.MaxPriceAccumulateFunction cannot be cast to org.drools.base.accumulators.AccumulateFunction at org.drools.compiler.PackageBuilderConfiguration.getAccumulateFunction(PackageBuilderConfiguration.java:489) at org.drools.rule.builder.dialect.java.JavaAccumulateBuilder.build(JavaAccumulateBuilder.java:108) ... My guess is this is a bug. For now I will just go back to implementing org.drools.base.accumulators.AccumulateFunction. cheers Steve -- Steven Williams Supervising Consultant Object Consulting Office: 8615 4500 Mob: 0439 898 668 Fax: 8615 4501 steven.williams(a)objectconsulting.com.au www.objectconsulting.com.au consulting | development | training | support our experience makes the difference