WordPress 2.8.5 & ‘Responsive Twenty Ten’ – error

So, According to the WordPress theme download page; the theme ‘Twenty Ten’ and it’s child theme/plugin ‘Responsive Twenty Ten’ are compatible with 2.8+

I’m stuck with using 2.8.5 at work, I don’t have an answer to why – but am.

I’ve uploaded both the plugin and the base theme manually – and was stoked to begin implementation of the graphical mock-up when;

Fatal error: Call to undefined function home_url() in /data/24/1/0/139/1815302/user/1967139/htdocs/wp-content/themes/twentyten 3/header.php on line 63

Anyone have any suggestions as to what causes this error and how to fix it?

Thanks for your response Chip; but I’m a little confused with your advice –

Your advising me to edit the header.php, but then your saying it will create more errors, so that’s not really an option then?

But your last suggestion seems like a good idea; how do I revert the theme to the old version? Is this something your suggesting I do in the code or is there a place I can download the old version?

Edit: On the download WP page for the ‘Responsive Child theme/plug in’ it says it’s WordPress 2.8+ compatible – the base version I downloaded didn’t specify it’s compatibility so it may very well be an updated version not compatible with 2.8 – though I feel like I’ve seen that theme for years, so hopefully I can find an older version and get it going with the child theme.

-cheers!

home_url() function is implemented in WordPress since version 3.0.0, and you are using version 2.8.5.

To fix this error edit wp-content/themes/twentyten 3/header.php file –

replace:

home_url();

with:

'http://'.$_SERVER["SERVER_NAME"]

This is hotfix, and i’m afraid you will receive more errors like this.

“Responsive Twenty Ten’ are compatible with 2.8+” – as you see it’s not true 🙂

Best solution is revert theme to old one, or install newest wordpress version.

EDIT

It would be better to use get_bloginfo( 'url' ) than $_SERVER data.