octobercms/october · error · SystemException

A widget class name ':name' has not been registered

Error message

A widget class name ':name' has not been registered

What it means

Error "A widget class name ':name' has not been registered" thrown in octobercms/october.

Source

Thrown at modules/backend/widgets/filter/HasFilterWidgets.php:57

            return null;
        }

        if (isset($this->filterWidgets[$scope->scopeName])) {
            return $this->filterWidgets[$scope->scopeName];
        }

        $widgetConfig = $this->makeConfig($scope->config);
        $widgetConfig->alias = $this->alias . studly_case($this->nameToId($scope->scopeName));
        $widgetConfig->previewMode = $this->previewMode;
        $widgetConfig->model = $this->scopeModels[$scope->scopeName] ?? null;
        $widgetConfig->isJsonable = $this->model->isJsonable($scope->scopeName);
        $widgetConfig->parentFilter = $this;

        $widgetName = $widgetConfig->widget;
        $widgetClass = $this->widgetManager->resolveFilterWidget($widgetName);

        if (!class_exists($widgetClass)) {
            throw new SystemException(Lang::get(
                'backend::lang.widget.not_registered',
                ['name' => $widgetClass]
            ));
        }

        $widget = $this->makeFilterWidget($widgetClass, $scope, $widgetConfig);

        return $this->filterWidgets[$scope->scopeName] = $widget;
    }

    /**
     * makeFilterWidget object with the supplied filter scope and widget configuration.
     * @param string $class Widget class name
     * @param mixed $scopeConfig A field name, an array of config or a FileScope object.
     * @param array $widgetConfig An array of config.
     * @return \Backend\Classes\FilterWidgetBase The widget object
     */
    public function makeFilterWidget($class, $scopeConfig = [], $widgetConfig = [])

View on GitHub (pinned to b608633a7e)

When it happens

Trigger: Thrown at modules/backend/widgets/filter/HasFilterWidgets.php:57 when the library encounters an invalid state.

Common situations: See trigger scenarios.

AI-assisted analysis of octobercms/october@b608633a7e (2026-08-21). Data as JSON: /api/errors/0b5b8bafec72c37b. Report an issue: GitHub.