ratchetphp/Ratchet · error · UnexpectedValueException

invalid data, remaining:

Error message

invalid data, remaining: 

What it means

PhpHandler::unserialize() decodes a 'php'-serialized session string, which requires every key to be delimited from its value by a '|' character. This \UnexpectedValueException fires when, at the current parse offset, no '|' remains in the remaining raw data — meaning the session payload is truncated, corrupted, or was not produced with the 'php' serialize_handler (e.g. php_serialized or php_binary format). The malformed segment cannot be mapped to a key/value pair, so parsing aborts with the leftover data reported in the message.

Solutions

1. Verify the session data was encoded with the same handler: encode with PhpHandler::serialize() and the ini setting session.serialize_handler=php before decoding.
2. Inspect the raw payload for truncation or corruption (missing '|' delimiters), e.g. log it, and discard/regenerate the session when it is invalid.
3. Wrap unserialize() in a try/catch for \UnexpectedValueException and treat it as an expired/invalid session: clear the data and start a fresh session instead of failing the request.

When it happens

Trigger: Thrown at src/Ratchet/Session/Serialize/PhpHandler.php:34 when the library encounters an invalid state.

Common situations: See trigger scenarios.

AI-assisted analysis of ratchetphp/Ratchet@e621c6c40b (2026-09-16). Data as JSON: /api/errors/a5e38a7385e14b5e. Report an issue: GitHub.

Appendix: source

Thrown at src/Ratchet/Session/Serialize/PhpHandler.php:34

            }
            $serialized = implode('', $preSerialized);
        }

        return $serialized;
    }

    /**
     * {@inheritdoc}
     * @link http://ca2.php.net/manual/en/function.session-decode.php#108037 Code from this comment on php.net
     * @throws \UnexpectedValueException If there is a problem parsing the data
     */
    public function unserialize($raw) {
        $returnData = array();
        $offset     = 0;

        while ($offset < strlen($raw)) {
            if (!strstr(substr($raw, $offset), "|")) {
                throw new \UnexpectedValueException("invalid data, remaining: " . substr($raw, $offset));
            }

            $pos     = strpos($raw, "|", $offset);
            $num     = $pos - $offset;
            $varname = substr($raw, $offset, $num);
            $offset += $num + 1;

            // try to unserialize one piece of data from current offset, ignoring any warnings for trailing data on PHP 8.3+
            // @link https://wiki.php.net/rfc/unserialize_warn_on_trailing_data
            $data = @unserialize(substr($raw, $offset));

            $returnData[$varname] = $data;
            $offset += strlen(serialize($data));
        }

        return $returnData;
    }
}

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