Why is there an error after installing laravel?

Question

Laravel

ubuntu
I install laravel via composer
clean, I launch it, immediately on the main page an error pops up
Warning: Header may not contain NUL bytes in /app/public/index.php on line 10
In index.php on line 10 I (and everyone)
define ('LARAVEL_START', microtime(true));
when running artisan, the same error occurs on line 4, in the artisan file, on line 4, the same line
define('LARAVEL_START', microtime(true));
version laravel 5.8.3 tried to install 5.7 5.6 same error

Answer 1

Here it is direct index.php also you launch? can first set up a web server.