The solution is indeed as mentioned in the other thread:
function _html_entity_decode_callback($match)
{
$charset = config_item('charset');
return $this->_html_entity_decode($match[0], strtoupper($charset));
}
The error is however caused because in codeigniter.php the Base4/5.php file is only loaded after the Input-class. In the Base4/5.php file the get_instance() function is written and it is conditionally loaded so it won’t be present until after it is loaded. Therefore the function is not present, yet. Another fix would probably be moving the IN=& load_class(‘Input’); after the loading of the base4/5.php file. I haven’t checked though. Neither would I really know the benefits of either solution.