octobercms/october · error · ApplicationException

cms::lang.theme.edit.not_found

Error message

cms::lang.theme.edit.not_found

What it means

ApplicationException thrown by `Page::getLayoutOptions()` (the form-widget source for the Layout dropdown) when `Theme::getEditTheme()` returns null — no editable theme could be resolved for the backend. This means the theme configuration itself is broken: no theme for the current site, no valid backend preference, and no usable active theme.

Source

Thrown at modules/cms/classes/Page.php:97

    /**
     * getCodeClassParent returns name of a PHP class to us a parent for the PHP class
     * created for the object's PHP section.
     * @return mixed Returns the class name or null.
     */
    public function getCodeClassParent()
    {
        return PageCode::class;
    }

    /**
     * getLayoutOptions returns a list of layouts available in the theme.
     * This method is used by the form widget.
     * @return array Returns an array of strings.
     */
    public function getLayoutOptions()
    {
        if (!($theme = Theme::getEditTheme())) {
            throw new ApplicationException(Lang::get('cms::lang.theme.edit.not_found'));
        }

        $layouts = Layout::listInTheme($theme, true);
        $result = [];
        $result[''] = Lang::get('cms::lang.page.no_layout');

        foreach ($layouts as $layout) {
            $baseName = $layout->getBaseFileName();

            if (FileDefinitions::isPathIgnored($baseName)) {
                continue;
            }

            $result[$baseName] = strlen($layout->name) ? $layout->name : $baseName;
        }

        return $result;
    }

View on GitHub (pinned to b608633a7e)

Solutions

1. Set the active theme in config/cms.php ('active_theme' => 'mytheme') or via the backend theme picker so an edit theme resolves.
2. Ensure `themes/mytheme/` actually exists with a valid theme.json and matches the configured code.
3. Reset the stuck backend preference by re-selecting a theme in the backend (or clearing the user preference) if it references a deleted theme.

Example fix

// config/cms.php — before
'active_theme' => '',

// after — must match a directory under themes/
'active_theme' => 'mytheme',

use Cms\Classes\Theme;

if (!Theme::getEditTheme()) {
    // don't build the page form at all without a resolvable edit theme
    abort(500, 'No editable theme configured. Set cms.active_theme first.');
}
// safe to call $page->getLayoutOptions()

try {
    $options = $page->getLayoutOptions();
} catch (ApplicationException $e) {
    // degrade gracefully: render form without the layout dropdown
    $options = ['' => 'No theme available'];
    Log::error('Layout options unavailable: ' . $e->getMessage());
}

When it happens

Trigger: Opening the page create/edit form when `themes/` is empty, the configured active theme folder doesn't exist, or the backend user's saved theme preference points at a deleted theme.

Common situations: Fresh installs that were never given a theme; cms.active_theme config pointing at a renamed theme; theme directory removed in a deploy; environment config (.env) missing so the wrong theme code resolves.

Related errors

• cms::lang.theme.edit.not_set
• cms::lang.theme.active.not_set
• cms::lang.theme.active.is_locked
• Cannot delete the active theme, try making another theme act
• cms::lang.template.not_found

AI-assisted analysis of octobercms/october@b608633a7e (2026-08-21). Data as JSON: /api/errors/c10a6f68e04e1d32. Report an issue: GitHub.