Can’t install plugin – strange message

I know that this plugin is not hosted in wordpress but I was hoping if someone could help me out anyway. Or at least tell me that it’s not just me with the problem.

If I try to install the plugin from this page: https://www.nathanrice.net/blog/serve-ie6-visitors-the-default-wordpress-theme/
I get the following message:
Incompatible archive PCLZIP_ERR_BAD_FORMAT (-10) : Unable to find End of Central Dir Record signature

The download link is broken so you have to use the code provided on the page:

<?php
/*
Plugin Name: Serve Default to IE6
Plugin URI: https://www.nathanrice.net/blog/serve-ie6-visitors-the-default-wordpress-theme
Description: This plugin will serve the default theme to any visitors using IE6.
Author: Nathan Rice
Author URI: https://www.nathanrice.net/
Version: 1.0
*/

add_filter('template', 'serve_default_to_iesix');
add_filter('option_template', 'serve_default_to_iesix');
add_filter('option_stylesheet', 'serve_default_to_iesix');
function serve_default_to_iesix($theme) {
	if(strpos($_SERVER['HTTP_USER_AGENT'], 'MSIE 6') !== false)
		$theme = 'default';

	return $theme;
}
?>

Thanks.