The server installation exe (CRM2016-Server-KB3203310-ENU-Amd64.exe) ran through with no errors but the DB did not update to version 8.1.1.1005

We then used Deployment Manager to do the update, this time an Error:
23:28:50|Verbose| Error occured in UpdateRollupFieldStoredProceduresInternal: Microsoft.Crm.CrmException: Error generating UiData for workflow:, id:00000000-0000-0000-0000-000000000000 ---> System.NullReferenceException: Object reference not set to an
instance of an object.
at Microsoft.Crm.Workflow.ObjectModel.UIDataGenerator.ReadEvaluateCondition(EvaluateCondition activity)
at Microsoft.Crm.Workflow.ObjectModel.UIDataGenerator.ReadExpression(Collection`1 activities, Type endActivityType, Boolean customActivity, Int32& activityIndex)
at Microsoft.Crm.Workflow.ObjectModel.UIDataGenerator.ReadRollupRuleStep(Sequence sequence)
at Microsoft.Crm.Workflow.ObjectModel.UIDataGenerator.ReadCompositeStep(String stepId, String description, Activity activity, Collection`1 variables)
at Microsoft.Crm.Workflow.ObjectModel.UIDataGenerator.ReadSingleStep(Activity activity)
at Microsoft.Crm.Workflow.ObjectModel.UIDataGenerator.GenerateWorkflowObjectModelFromXaml()
--- End of inner exception stack trace ---
at Microsoft.Crm.Workflow.ObjectModel.UIDataGenerator.GenerateWorkflowObjectModelFromXaml()
at Microsoft.Crm.Workflow.ObjectModel.UIDataGenerator.GenerateUIData(ExecutionContext context)
at Microsoft.Crm.ObjectModel.RollupPropertiesService.GetWorkflowStep(AttributeDescriptionPropertyBag attributeInfo, ExecutionContext context, ICalculatedFieldInfo& calculatedFieldInfo)
at Microsoft.Crm.ObjectModel.RollupPropertiesService.GenerateIncrementalStoredProc(RollupProperties rollupProperties, AttributeDescriptionPropertyBag attributeInfo, Boolean isCreate, ExecutionContext context, Boolean isInstallOrPatch)
Deployment gurus, any ideas?
Eric UNG [Senior Analyst Programmer :: Sydney, Australia]