octobercms/october · error · ApplicationException

Model ':class' does not contain a definition for ':relation'

Error message

Model ':class' does not contain a definition for ':relation'.

What it means

Error "Model ':class' does not contain a definition for ':relation'." thrown in octobercms/october.

Source

Thrown at modules/backend/widgets/Lists.php:1451

        $this->filterCallbacks[] = $filter;
    }

    //
    // Helpers
    //

    /**
     * isColumnRelated checks if column refers to a relation of the model, with a toggle
     * switch for checking only relationships with multiple records.
     */
    protected function isColumnRelated(ListColumn $column, bool $isMulti = false): bool
    {
        if (!$column->relation || $this->isColumnPivot($column)) {
            return false;
        }

        if (!$this->model->hasRelation($column->relation)) {
            throw new ApplicationException(Lang::get(
                'backend::lang.model.missing_relation',
                ['class'=>get_class($this->model), 'relation'=>$column->relation]
            ));
        }

        if ($isMulti) {
            return !$this->model->isRelationTypeSingular($column->relation);
        }

        return true;
    }

    /**
     * isColumnPivot checks if a column refers to a pivot model specifically.
     */
    protected function isColumnPivot(ListColumn $column): bool
    {
        if (!$column->relation || $column->relation !== 'pivot') {

View on GitHub (pinned to b608633a7e)

When it happens

Trigger: Thrown at modules/backend/widgets/Lists.php:1451 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/55511d44e4912b24. Report an issue: GitHub.