WebFlow: Error semasa transition utk hasil evaluate Boolean

ERROR:

org.springframework.webflow.engine.NoMatchingTransitionException: No transition was matched on the event(s) signaled by the [1] action(s) that executed in this action state 'checkAuthorization' of flow 'marking/apr'; transitions must be defined to handle action result outcomes -- possible flow configuration error? Note: the eventIds signaled were: 'array<String>['no']', while the supported set of transitional criteria for this action state is 'array<TransitionCriteria>[true, false]'

Punca:

Silap nilai transition semasa evaluate function yang memulangkan nilai Boolean

 <action-state id="checkAuthorization">
     <evaluate expression="aprService.isAuthorized(requestScope.viewerId, requestScope.aprId)" />
     <transition on="true" to="markingEntry" />
     <transition on="false" to="summary" />
</action-state>

Sepatutnya true dan false itu ditukarkan kepada yes dan no.