I've created my laravel project as follows:
laravel new my_app
This creates my project using laravel version 8. As I want to use Laravel 7, I modified composer.json:
"laravel/framework": "^7.0",
After that I run:
composer update
which ends with the error described (Class Illuminate\Support\Facades\RateLimiter not found )
In fact, that class doesn't exist in Support facade. Shouldn't downgrade process correct this?
No, this is from code in your application; specifically your App\Providers\RouteServiceProvider. Everything that isn't in vendor is considered your application and is not touched by any upgrade or downgrade. The laravel/laravel package only sets up your application skeleton for you. You can install Laravel 7 specifically with composer create-project --prefer-dist laravel/laravel:^7.0 yourproject; you can find the instructions in the install guide for Laravel 7.
Otherwise you will need to potentially copy the Service Providers from laravel/laravel version 7 into your application so you are not using providers from Laravel 8 as some things have changed and some new features were introduced. And there would be other changes as well.
Laravel 7.x Docs - Installation - via Composer Create-Project composer create-project
