Class 'Symfony\Component\EventDispatcher\Event' not found

i was get bug from Event when i upload my image in server

Error
Class 'Symfony\Component\EventDispatcher\Event' not found in line 10

and this my code call Event

 public static function uploadFileStore($file, $nameDir, $redirect = 'Admin\Admin', $params = [])
    {
        $storage = \App\Common\Factory\Storage::getInstance()->getDriver();
        $rand = rand(1, 100000);
        $milliseconds = self::milliseconds();
        $file_name = $nameDir . '/' . $milliseconds . '-' . $rand . '-' . Utility::makeFilename($file->getClientOriginalName());
        try {
            $storage->put($file_name, $file->path());
            return $attachFile = $file_name;
        } catch (S3Exception $e) {
            return redirect()->action($redirect, $params)
                ->withError(__('messages.upload.validate.upload_error'));
        }
    }

code die after calling put method. and this is put method

public function put($key, $filePath)
    {
        $log = new Log('aws');
        try {
            $client = S3Client::factory($this->getConfigs());
            $response = $client->putObject(array(
                'Bucket' => $this->getBucket(),
                'Key' => $key,
                'SourceFile' => $filePath,
                'ContentType' => mimetype_from_filename($key),
            ));


            $log->addRecord("Success: put file", Log::INFO, ['data' => $response]);

            return $response;
        } catch (S3Exception $e) {
            $log->addRecord("Error: put file", Log::ERROR, ['data' => $e]);
        }
    }

and i try using another class

use Illuminate\Http\Testing\MimeType;

and i change method calling $key

'ContentType' => MimeType::from($key),

this code in line 10 in file vendor/guzzle/guzzle/src/Guzzle/Common/Event.php