[rules-users] DSL in 3.1.0 m1

Hi, I tried to run TroubleTicketExampleWithDSL example in 3.1.0M1 but it displayed following error: org.drools.rule.InvalidRulePackage: unknown:2:0 required (...)+ loop (decision=2) did not match anything; token=[@8,29:36='expander',<31>,2:0] at org.drools.rule.Package.checkValidity(Package.java:367) at org.drools.common.AbstractRuleBase.addPackage (AbstractRuleBase.java:244) at com.sample.TroubleTicketExampleWithDSL.main (TroubleTicketExampleWithDSL.java:25) Exception in thread "main" The same example is ok in 3.0.5. Can anyone help me with it? Thanks a lot. fanghong