Hi Kevin,
Have you made a file named 'en_gb' which goes inside the folder 'language'?
This file should contain this:
<?php
// Are we in Localization class? If not break!
if(!isset($this) || !($this instanceof Localization)) {
throw new InvalidInstanceError('$this', $this, 'Localization', "File '" . __FILE__ . "' can be included only from Localization class");
} // if
?>
And then, have you made the '_config.php' file inside the 'en_gb' folder which should contain something like this?
<?php
return array(
'_language_name' => 'English (U.K.)',
'_ext_language_file' => 'ext-lang-en-min.js',
);
?>
Best regards,
Francisco