Why am I getting Stack Trace when I open Horizon?

Question

I allocate enough memory for this. in php.ini memory_limit = 3G I don't understand why this happens. If anyone has come across this problem. When I run рorizon with these settings.

'defaults' => [
    'supervisor-1' => [
        'connection' => 'redis',
        'queue' => ['default'],
        'balance' => 'auto',
        'maxProcesses' => 1,
        'maxTime' => 0,
        'maxJobs' => 0,
        'memory' => 2048,
        'tries' => 1,
        'timeout' => 200,
        'nice' => 0,
    ],
],

'environments' => [
 
    'local' => [
        'supervisor-1' => [
            'maxProcesses' => 400,
        ],
    ],
],

I am getting next errors:

Stack trace:
#0 /var/www/html/vendor/composer/ClassLoader.php(571): include()
#1 /var/www/html/vendor/composer/ClassLoader.php(428): Composer\Autoload\includeFile()
#2 /var/www/html/vendor/symfony/console/Input/ArgvInput.php(41): Composer\Autoload\ClassLoader->loadClass()
#3 /var/www/html/vendor/composer/ClassLoader.php(571): include('...')
#4 /var/www/html/vendor/composer/ClassLoader.php(428): Composer\Autoload\includeFile()
#5 /var/www/html/artisan(36): Composer\Autoload\ClassLoader->loadClass()
#6 {main}
  thrown in /var/www/html/vendor/symfony/console/Input/Input.php on line 28
PHP Warning:  require(/var/www/html/vendor/composer/autoload_static.php): Failed to open stream: Input/output error in /var/www/html/vendor/composer/autoload_real.php on line 33
PHP Fatal error:  Uncaught Error: Failed opening required '/var/www/html/vendor/composer/autoload_static.php' (include_path='.:/usr/share/php') in /var/www/html/vendor/composer/autoload_real.php:33
Stack trace:
#0 /var/www/html/vendor/autoload.php(7): ComposerAutoloaderInit178bef08a42940d39635a033dd116c7e::getLoader()
#1 /var/www/html/artisan(18): require('...')
#2 {main}
  thrown in /var/www/html/vendor/composer/autoload_real.php on line 33
PHP Warning:  require_once(/var/www/html/vendor/composer/autoload_real.php): Failed to open stream: Input/output error in /var/www/html/vendor/autoload.php on line 5
PHP Fatal error:  Uncaught Error: Failed opening required '/var/www/html/vendor/composer/autoload_real.php' (include_path='.:/usr/share/php') in /var/www/html/vendor/autoload.php:5
Stack trace:
#0 /var/www/html/artisan(18): require()
#1 {main}
  thrown in /var/www/html/vendor/autoload.php on line 5
PHP Warning:  include(/var/www/html/vendor/vlucas/phpdotenv/src/Repository/Adapter/AdapterInterface.php): Failed to open stream: Input/output error in /var/www/html/vendor/composer/ClassLoader.php on line 571
PHP Warning:  include(): Failed opening '/var/www/html/vendor/composer/../vlucas/phpdotenv/src/Repository/Adapter/AdapterInterface.php' for inclusion (include_path='.:/usr/share/php') in /var/www/html/vendor/composer/ClassLoader.php on line 571
PHP Warning:  include(/var/www/html/vendor/laravel/framework/src/Illuminate/Support/Reflector.php): Failed to open stream: Input/output error in /var/www/html/vendor/composer/ClassLoader.php on line 571
PHP Warning:  include(): Failed opening '/var/www/html/vendor/composer/../laravel/framework/src/Illuminate/Support/Reflector.php' for inclusion (include_path='.:/usr/share/php') in /var/www/html/vendor/composer/ClassLoader.php on line 571
PHP Fatal error:  Uncaught Error: Class "Illuminate\Support\Reflector" not found in /var/www/html/vendor/laravel/framework/src/Illuminate/Foundation/Exceptions/Handler.php:227

I need to process a large number of requests and 400 is the optimal number of processes for proper operation

But when the maxProcess => 7 parameter is set, everything works fine. But it's too slow

All files are in place.

-rwxrwxrwx 1 sail sail 779502 Mar 12 22:33 autoload_static.php

-rwxrwxrwx 1 sail sail   2629 Mar 12 18:41 autoload_real.php

-rwxrwxrwx 1 sail sail  4453 Mar  8 16:17 Reflector.php