bug in php artisan serve

hello every one

when the setup with composer has finished i type the command php artisan
serve i have this error:
** In ServeCommand.php line 35:

   [ErrorException]
   chdir (): No such file or directory (errno 2)
**

I type --verbose to see the trace of the error:

I get this:

 **Exception trace:
 Illuminate\Foundation\Bootstrap\HandleExceptions->handleError() at n/a:n/a
 chdir() at C:\wamp642\www\atlantica\vendor\laravel\framework\src\Illuminate\Foundation\Console\ServeCommand.php:35
 Illuminate\Foundation\Console\ServeCommand->handle() at n/a:n/a
 call_user_func_array() at C:\wamp642\www\atlantica\vendor\laravel\framework\src\Illuminate\Container\BoundMethod.php:29
 Illuminate\Container\BoundMethod::Illuminate\Container\{closure}() at C:\wamp642\www\atlantica\vendor\laravel\framework\src\Illuminate\Container\BoundMethod.php:87
 Illuminate\Container\BoundMethod::callBoundMethod() at C:\wamp642\www\atlantica\vendor\laravel\framework\src\Illuminate\Container\BoundMethod.php:31
 Illuminate\Container\BoundMethod::call() at C:\wamp642\www\atlantica\vendor\laravel\framework\src\Illuminate\Container\Container.php:549
 Illuminate\Container\Container->call() at C:\wamp642\www\atlantica\vendor\laravel\framework\src\Illuminate\Console\Command.php:183
 Illuminate\Console\Command->execute() at C:\wamp642\www\atlantica\vendor\symfony\console\Command\Command.php:251
 Symfony\Component\Console\Command\Command->run() at C:\wamp642\www\atlantica\vendor\laravel\framework\src\Illuminate\Console\Command.php:170
 Illuminate\Console\Command->run() at C:\wamp642\www\atlantica\vendor\symfony\console\Application.php:946
 Symfony\Component\Console\Application->doRunCommand() at C:\wamp642\www\atlantica\vendor\symfony\console\Application.php:248
 Symfony\Component\Console\Application->doRun() at C:\wamp642\www\atlantica\vendor\symfony\console\Application.php:148
 Symfony\Component\Console\Application->run() at C:\wamp642\www\atlantica\vendor\laravel\framework\src\Illuminate\Console\Application.php:88
 Illuminate\Console\Application->run() at C:\wamp642\www\atlantica\vendor\laravel\framework\src\Illuminate\Foundation\Console\Kernel.php:121
 Illuminate\Foundation\Console\Kernel->handle() at C:\wamp642\www\atlantica\artisan:35

**

and then i update the composer but i get another error:

**c:\wamp642\www\atlantica>composer update
Loading composer repositories with package information
Updating dependencies (including require-dev)
Nothing to install or update
Generating autoload files
> php artisan clear-compiled
The compiled services & packages files have been removed.
> php artisan optimize

In Filesystem.php line 84:

  Illuminate\Filesystem\Filesystem::getRequire(): Failed opening required 'C:\wamp642\www\atlantica\bootstrap/cache/packages.php' (include_path='.;C:\php\pear')


Script php artisan optimize handling the post-update-cmd event returned with error code 255
**

please help.