getgrav/grav · error · RuntimeException

Theme name not provided.

Error message

Theme name not provided.

What it means

Themes::get($name) looks up a theme's configuration and blueprints; it throws immediately when the name is empty (null, '', 0) because every later step (themes://{$name}/blueprints, themes://{$name}/{$name}.yaml) is meaningless without it. Note the asymmetry: a theme that is named but does not exist returns null; only a missing name throws.

Source

Thrown at system/src/Grav/Common/Themes.php:172

                $list[$theme] = $result;
            }
        }
        ksort($list, SORT_NATURAL | SORT_FLAG_CASE);

        return $list;
    }

    /**
     * Get theme configuration or throw exception if it cannot be found.
     *
     * @param  string $name
     * @return Data|null
     * @throws RuntimeException
     */
    public function get($name)
    {
        if (!$name) {
            throw new RuntimeException('Theme name not provided.');
        }

        $blueprints = new Blueprints('themes://');
        $blueprint = $blueprints->get("{$name}/blueprints");

        // Load default configuration.
        $file = CompiledYamlFile::instance("themes://{$name}/{$name}" . YAML_EXT);

        // ensure this is a valid theme
        if (!$file->exists()) {
            return null;
        }

        // Find thumbnail.
        $thumb = "themes://{$name}/thumbnail.jpg";
        $path = $this->grav['locator']->findResource($thumb, false);

        if ($path) {

View on GitHub (pinned to 6040efed04)

Solutions

1. Pass the real theme name, usually $grav['config']->get('system.pages.theme') or a literal like 'quark'
2. Guard or default the value before calling: $name = trim((string) $name); if ($name !== '') { ... }
3. If the value comes from config, fix the config key being read (e.g. system.pages.theme, not a nonexistent path)

Example fix

// before: config key typo yields null
$data = $themes->get($grav['config']->get('system.pages.theme.missing'));

// after
$name = $grav['config']->get('system.pages.theme') ?: 'quark';
$data = $name ? $themes->get($name) : null;

$name = is_string($name) ? trim($name) : '';
if ($name === '') {
    // skip, default, or raise your own clearer error — do not call Themes::get()
    $name = $grav['config']->get('system.pages.theme') ?: 'quark';
}
$data = $grav['themes']->get($name); // null means unknown-but-named theme

function isNonEmptyThemeName(mixed $name): bool
{
    return is_string($name) && trim($name) !== '';
}

try { $themes->get($name); } catch (RuntimeException $e) { // programming error: log with backtrace, do not use as control flow
    $grav['debugger']->addException($e); return null; }

When it happens

Trigger: Calling $themes->get('') / ->get(null) / ->get(0) from custom code; passing an unset config key like $config->get('system.pages.theme.missing') (returns null); feeding a loop variable or request parameter that arrived empty; an admin/plugin enumerating themes where the iteration produced a blank entry.

Common situations: Plugins or Twig code that looks up a theme from unvalidated config or user input; refactors where a variable was renamed and now passes null; CLI scripts iterating theme folders with empty names.

Related errors

• {theme} theme could not be found
• Stream '{$type}' could not be initialized.
• Failed to save file '%s': %s
• Cannot save data, string required
• 500

AI-assisted analysis of getgrav/grav@6040efed04 (2026-08-17). Data as JSON: /api/errors/73d349e05a885498. Report an issue: GitHub.