yiisoft/yii2 · error · UnknownPropertyException

Setting unknown property: {class}::{name}

Error message

Setting unknown property: {class}::{name}

What it means

The __set() counterpart of the unknown-property read error: assigning to a name that has no setter, no getter, and is not a public member throws UnknownPropertyException('Setting unknown property: C::p'). Because Yii configures objects by assigning each config-array key through __set(), this is the classic symptom of a misspelled or unsupported key in a components/config array - the message names the component class and the offending key.

Source

Thrown at framework/base/BaseObject.php:164

     * Sets value of an object property.
     *
     * Do not call this method directly as it is a PHP magic method that
     * will be implicitly called when executing `$object->property = $value;`.
     * @param string $name the property name or the event name
     * @param mixed $value the property value
     * @throws UnknownPropertyException if the property is not defined
     * @throws InvalidCallException if the property is read-only
     * @see __get()
     */
    public function __set($name, $value)
    {
        $setter = 'set' . $name;
        if (method_exists($this, $setter)) {
            $this->$setter($value);
        } elseif (method_exists($this, 'get' . $name)) {
            throw new InvalidCallException('Setting read-only property: ' . get_class($this) . '::' . $name);
        } else {
            throw new UnknownPropertyException('Setting unknown property: ' . get_class($this) . '::' . $name);
        }
    }

    /**
     * Checks if a property is set, i.e. defined and not null.
     *
     * Do not call this method directly as it is a PHP magic method that
     * will be implicitly called when executing `isset($object->property)`.
     *
     * Note that if the property is not defined, false will be returned.
     * @param string $name the property name or the event name
     * @return bool whether the named property is set (not null).
     * @see https://www.php.net/manual/en/function.isset.php
     */
    public function __isset($name)
    {
        $getter = 'get' . $name;
        if (method_exists($this, $getter)) {

View on GitHub (pinned to 66f00d18a2)

Solutions

1. Compare the failing key (shown in the message) with the class's real property list in its source or @property docblock and fix the spelling
2. Verify the 'class' value in that config block is really the class you intend to configure
3. Confirm the installed package version supports the option (composer show) and update, or find the legacy option name

Example fix

// before
'components' => [
    'cache' => ['class' => \yii\caching\DbCache::class, 'cacheTabl' => 'cache'],
],

// after
'components' => [
    'cache' => ['class' => \yii\caching\DbCache::class, 'cacheTable' => 'cache'],
],

foreach ($config as $key => $value) {
    if (strncmp($key, 'on ', 3) !== 0 && strncmp($key, 'as ', 3) !== 0
        && !$object->canSetProperty($key) && !isset($object->$key)) {
        unset($config[$key]); // or throw with the key name
    }
}

function isWritableConfigKey(\yii\base\BaseObject $object, string $key): bool
{
    return strncmp($key, 'on ', 3) === 0
        || strncmp($key, 'as ', 3) === 0
        || $object->canSetProperty($key);
}

try {
    Yii::configure($object, $config);
} catch (\yii\base\UnknownPropertyException $e) {
    Yii::error('Config key rejected: ' . $e->getMessage());
    throw $e;
}

When it happens

Trigger: 'components' => ['cache' => ['class' => \yii\caching\DbCache::class, 'cacheTabl' => 'cache']] (typo); using a config option that exists only in a newer 2.0.x release than the one installed; a 'class' key pointing to a different class than you think, so its option keys do not apply; trying to set private or static members via instance syntax.

Common situations: Long config files with typos; snippets copied from docs written for another version; extension options renamed between releases; ArrayHelper::merge dropping or relocating nested keys.

Related errors

• Getting unknown property: {class}::{name}
• Calling unknown method: {class}::{name}()
• 'Getting write-only property: ' . get_class($this) . '::' .
• Setting read-only property: {class}::{name}
• Unsetting read-only property: {class}::{name}

AI-assisted analysis of yiisoft/yii2@66f00d18a2 (2026-08-17). Data as JSON: /api/errors/1c81d16fef52de5b. Report an issue: GitHub.