将laravel项目从一台服务器移动到另一台服务器

Basically I had been working on a laravel project for about a year.Later on, I transferred the laravel project to a new pc.

When I try php artisan serve, I get:

PHP Warning:  require(C:\xampp\htdocs\mysite\vendor\composer/../symfony/var-dumper/Resources/functions/dump.php): failed to open stream: No such file or directory in C:\xampp\htdocs\mysite\vendor\composer\autoload_real.php on line 66

Warning: require(C:\xampp\htdocs\mysite\vendor\composer/../symfony/var-dumper/Resources/functions/dump.php): failed to open stream: No such file or directory in C:\xampp\htdocs\mysite\vendor\composer\autoload_real.php on line 66
PHP Fatal error:  require(): Failed opening required 'C:\xampp\htdocs\mysite\vendor\composer/../symfony/var-dumper/Resources/functions/dump.php' (include_path='C:\xampp\php\PEAR') in C:\xampp\htdocs\mysite\vendor\composer\autoload_real.php on line 66

Fatal error: require(): Failed opening required 'C:\xampp\htdocs\mysite\vendor\composer/../symfony/var-dumper/Resources/functions/dump.php' (include_path='C:\xampp\php\PEAR') in C:\xampp\htdocs\mysite\vendor\composer\autoload_real.php