Fatal error: Using $this when not in object context

[eluser]coolfactor[/eluser]
Generally discouraged to do it that way. Do that in your controller, assign the value to a variable that you pass the view.

In your controller:

Code:

// get base_view variable
$data['base_view'] = $this->config->view('base_view');

// load header view
$data['header'] = $this->load->view('header', $data, TRUE);

// load main template
$this->load->view('template', $data);

In your header.php view:

Code:

<link href="<?=$base_view;?>style.css" rel="stylesheet" type="text/css">