void AddExternalIssue ( [EStackIssueSeverity](API\Plugins\NiagaraEditor\ViewModels\Stack\EStackIssueSeverity) Severity, const [FText](API\Runtime\Core\Internationalization\FText) & SummaryText, const [FText](API\Runtime\Core\Internationalization\FText) & Description, bool bCanBeDismissed )