require(vendor/autoload.php): failed to open stream

Question

I know that this issue has been posted many times, but for me it seems to be a different problem.

Indeed, this error

Warning: require(vendor/autol

Answer 1

This error occurs because of missing some files and the main reason is "Composer"

First Run these commands in CMD

php -r "copy('https://getcomposer.org/installer', 'composer-setup.php');"
php -r "if (hash_file('sha384', 'composer-setup.php') === 'e0012edf3e80b6978849f5eff0d4b4e4c79ff1609dd1e613307e16318854d24ae64f26d17af3ef0bf7cfb710ca74755a') { echo 'Installer verified'; } else { echo 'Installer corrupt'; unlink('composer-setup.php'); } echo PHP_EOL;"
php composer-setup.php
php -r "unlink('composer-setup.php');"

Then Create a New project
Example:

D:/Laravel_Projects/New_Project
laravel new New_Project

After that start the server using

php artisan serve