[ https://issues.redhat.com/browse/DROOLS-5438?page=com.atlassian.jira.plug... ] Maciej Swiderski commented on DROOLS-5438: ------------------------------------------ [~tari_manga] is this actually breaking the spec? In the screenshot you attached it states that list can be empty and that results in null outcome of the function. But right now the engine throws an exception and the decision is not evaluated at all which later on results with    {code:java} 2020-08-20 17:03:21,797 [main] ERROR FEEL ERROR while evaluating literal expression 'sum(for i in List of Conditions return Comorbidity... [string clipped after 50 chars, total length is 60]': The parameter 'list', in function sum(), cannot be null or empty. 2020-08-20 17:03:21,813 [main] ERROR Unable to evaluate decision 'C Score' as it depends on decision 'Comorbidity Score for Listed Conditions' 2020-08-20 17:03:21,813 [main] ERROR Unable to evaluate decision 'LACE Score' as it depends on decision 'C Score' 2020-08-20 17:03:21,813 [main] ERROR Unable to evaluate decision 'Risk of Re-Admission' as it depends on decision 'LACE Score' {code} -- This message was sent by Atlassian Jira (v7.13.8#713008)