Error App\\Application when upgrading version of CakePHP from 3.6 to 3.7

My application is working if the version of my cake 3.6.7 then after upgrading it to version 3.7.* it causes an error when running my application it just show error 500.

here’s the error at apache:

PHP Fatal error: Uncaught Error: Class ‘App\Application’ not found in /var/www/html/test/webroot/index.php:37\nStack trace:\n#0 {main}\n thro