CodeIgniter not loading the core

This is outrages, I have been trying to configure CodeIgniter V3.1.3 for 3 hours now.
Everything was working perfectly I uploaded it on the web, changed the base_url and it doesn't won't to work:

Code:

An uncaught Exception was encountered

Type: Error

Message: Call to undefined function base_url()

Filename: /var/www/html/sub/application/views/errors/html/error_404.php

Line Number: 184

Backtrace:

File: /var/www/html/sub/index.php
Line: 316
Function: require_once

When i print the the path for loading the core file:

Code:

BASEPATH.'core/CodeIgniter.php'

This is what i get:

Code:

/var/www/html/sub/system/core/CodeIgniter.php

The path is ok

Here my .htaccess

Code:

RewriteEngine On
RewriteBase /sub/
RewriteCond %{REQUEST_FILENAME} !-f
RewriteCond %{REQUEST_FILENAME} !-d
RewriteRule ^(.*)$ index.php/$1 [L]

Tried

• I tried switching to all types of uri_protocol.
  
• Multiple SO answers revolve around htaccess
  

Server

• Debian Jessie
  
• PHP 7
  
• Apache 2.4
  

I included the url helper.

So everything works normally on Local, I re uploaded all the files 2-3 times. At this point I thinks its something to do with the server

Code:

An uncaught Exception was encountered

Type: Error

Message: Call to undefined function base_url()

Filename: /var/www/html/sub/application/views/errors/html/error_404.php

Line Number: 184

Stock version of this file has 64 lines.