Seldaek/monolog · error · UnexpectedValueException

The nested handler of type {class} does not support formatte

Error message

The nested handler of type {class} does not support formatters.

What it means

Error "The nested handler of type {class} does not support formatters." thrown in Seldaek/monolog.

Source

Thrown at src/Monolog/Handler/FilterHandler.php:178

            $this->handler = $handler;
        }

        return $this->handler;
    }

    /**
     * @inheritDoc
     */
    public function setFormatter(FormatterInterface $formatter): HandlerInterface
    {
        $handler = $this->getHandler();
        if ($handler instanceof FormattableHandlerInterface) {
            $handler->setFormatter($formatter);

            return $this;
        }

        throw new \UnexpectedValueException('The nested handler of type '.\get_class($handler).' does not support formatters.');
    }

    /**
     * @inheritDoc
     */
    public function getFormatter(): FormatterInterface
    {
        $handler = $this->getHandler();
        if ($handler instanceof FormattableHandlerInterface) {
            return $handler->getFormatter();
        }

        throw new \UnexpectedValueException('The nested handler of type '.\get_class($handler).' does not support formatters.');
    }

    public function reset(): void
    {
        $this->resetProcessors();

View on GitHub (pinned to 57eb102834)

When it happens

Trigger: Thrown at src/Monolog/Handler/FilterHandler.php:178 when the library encounters an invalid state.

Common situations: See trigger scenarios.

AI-assisted analysis of Seldaek/monolog@57eb102834 (2026-08-17). Data as JSON: /api/errors/0ed3a6a7fc03bb49. Report an issue: GitHub.