With the new Madrid problem state model when a problem ticket closes any related incidents that are in a state of 'On Hold' with a reason of 'Awaiting Problem' are no longer closing.
If there are any fields that are mandatory upon resolving an incident other than the close notes and close code the update to resolve the incident, once the related problem is closed, is being aborted and not working properly. The updates to the incident resolution fields are being made by the script action 'Update Incident when Problem closes' which is an event called 'problem.state_change' which is triggered by the business rule 'Raise an event when State changes.'
With the new problem state model you need to modify the script action to update any mandatory fields you have added to the incident form in order to resolve the incident. Previously the BR 'SNC - ITIL - Update Related Incidents' was used to update the incidents related to a problem ticket.