Only variables should be assigned by reference with function
This is an codeigniter bug in which the old version does not support anymore the mysql.
You can go to file: system/core/Loader.php Then file: system/core/Common.php Line 190 there should be:
//function is_loaded($class = '') >>> Edit this one like the expression below
function &is_loaded($class = '')
function &is_loaded($class = '')
After that go to file: application/config/database.php and change the following below:
//$db['default']['dbdriver'] = 'mysql'; >>> Edit this one like the expression below.
$db['default']['dbdriver'] = 'mysqli';
I hope it works
Please see this url
https://github.com/bcit-ci/CodeIgniter/issues/904
You can go to file: system/core/Loader.php
Then
file: system/core/Common.php
Line 190 there should be:
function &is_loaded($class = '')