laravel 8 php artisan not working

when i ran php artisan serve on laravel 8 i got this error i ran composer update still same error

PHP Warning:  require(C:\Users\ADEALA\Desktop\Experience-5-21anonymous-secret-confessions\Upload\vendor\composer/../phpunit/phpunit/src/Framework/Assert/Functions.php): Failed to open stream
: No such file or directory in C:\Users\ADEALA\Desktop\Experience-5-21anonymous-secret-confessions\Upload\vendor\composer\autoload_real.php on line 71

Warning: require(C:\Users\ADEALA\Desktop\Experience-5-21anonymous-secret-confessions\Upload\vendor\composer/../phpunit/phpunit/src/Framework/Assert/Functions.php): Failed to open stream: No
such file or directory in C:\Users\ADEALA\Desktop\Experience-5-21anonymous-secret-confessions\Upload\vendor\composer\autoload_real.php on line 71
PHP Fatal error:  Uncaught Error: Failed opening required 'C:\Users\ADEALA\Desktop\Experience-5-21anonymous-secret-confessions\Upload\vendor\composer/../phpunit/phpunit/src/Framework/Assert/
Functions.php' (include_path='C:\xampp\php\PEAR') in C:\Users\ADEALA\Desktop\Experience-5-21anonymous-secret-confessions\Upload\vendor\composer\autoload_real.php:71
Stack trace:
#0 C:\Users\ADEALA\Desktop\Experience-5-21anonymous-secret-confessions\Upload\vendor\composer\autoload_real.php(61): composerRequire1b7d20ae2d5dd48437ca659cec5cf965('ec07570ca5a8121...', 'C:
\Users\ADEALA...')
#1 C:\Users\ADEALA\Desktop\Experience-5-21anonymous-secret-confessions\Upload\vendor\autoload.php(7): ComposerAutoloaderInit1b7d20ae2d5dd48437ca659cec5cf965::getLoader()
#2 C:\Users\ADEALA\Desktop\Experience-5-21anonymous-secret-confessions\Upload\artisan(18): require('C:\Users\ADEALA...')
#3 {main}
  thrown in C:\Users\ADEALA\Desktop\Experience-5-21anonymous-secret-confessions\Upload\vendor\composer\autoload_real.php on line 71

Fatal error: Uncaught Error: Failed opening required 'C:\Users\ADEALA\Desktop\Experience-5-21anonymous-secret-confessions\Upload\vendor\composer/../phpunit/phpunit/src/Framework/Assert/Funct
ions.php' (include_path='C:\xampp\php\PEAR') in C:\Users\ADEALA\Desktop\Experience-5-21anonymous-secret-confessions\Upload\vendor\composer\autoload_real.php:71
Stack trace:
#0 C:\Users\ADEALA\Desktop\Experience-5-21anonymous-secret-confessions\Upload\vendor\composer\autoload_real.php(61): composerRequire1b7d20ae2d5dd48437ca659cec5cf965('ec07570ca5a8121...', 'C:
\Users\ADEALA...')
#1 C:\Users\ADEALA\Desktop\Experience-5-21anonymous-secret-confessions\Upload\vendor\autoload.php(7): ComposerAutoloaderInit1b7d20ae2d5dd48437ca659cec5cf965::getLoader()
#2 C:\Users\ADEALA\Desktop\Experience-5-21anonymous-secret-confessions\Upload\artisan(18): require('C:\Users\ADEALA...')
#3 {main}
  thrown in C:\Users\ADEALA\Desktop\Experience-5-21anonymous-secret-confessions\Upload\vendor\composer\autoload_real.php on line 71