failed to open stream: No such file or directory in \wp-includes\pomo\translations.php on line 10 code example

Example: failed to open stream: No such file or directory in artisan on line 18

The error is due to missing vendor folder.
You just need to run `composer install` in the project directory which will 
create a folder named vendor which will have all composer libraries and 
`autoload.php` file.