haha. That is pretty funny. Sorry about your time on that though. I guess we're all going to say namecheap is not recommended. I want to start compiling a list of recommended hosting providers. We've bent over backwards building compatibility with everything from apache to nginx and dozens of providers, but that's just uncalled for.
Ok, so I had issues with Error 500. Maybe this helps to someone:
I got Error 500 every time I tryed to access any page other than index.php. Error occured when I copyed login.php from users to usersc or when I copyed index.php and renamed it. Only index.php was working correctly.
Solution: in every page you create you must have some php code
<?php
require_once 'users/init.php';
require_once $abs_us_root.$us_url_root.'users/includes/header.php';
require_once $abs_us_root.$us_url_root.'users/includes/navigation.php';
?>
change code above with the one below
<?php
require_once $_SERVER['DOCUMENT_ROOT'].'/users/init.php';
require_once $abs_us_root.$us_url_root.'users/includes/header.php';
require_once $abs_us_root.$us_url_root.'users/includes/navigation.php';
?>
Note the / before users/init.php!
Apache2 on Debian 8
