I'm getting "Fatal Error: Call to undefined function path_to_subtheme()

Without more info, I’m not going to be able to figure out what is going on. Make sure you followed all the steps when you created a sub-theme. http://drupal.org/node/201423

Hi mimetic2

This is not a bug, there is a mistake in the Zen subtheme docs (http://drupal.org/node/201423), which you probably followed. You want to change path_to_zentheme() call to path_to_theme(), not path_to_theme() to path_to_subtheme(). See my comment: http://drupal.org/node/201423#comment-744166.

The comments inside the zen template.php are also contradictory to the docs.

Pawel, please don’t confuse the Drupal 6 version with the Drupal 5 version of Zen.

There is no mistake in the documentation. The online documentation is for Drupal 5 (note the “Drupal 5.x” category text in the top right corner of the page). And mimetic’s question is about the Drupal 5 version.

I'm getting this as well.

I'm following a video tutorial @:

http://www.theartlab.net/drupal-school-themeing-zen

working off a vanilla install of drupal 5.7

I've renamed the zen folder as per the tutorial to 'zen-theme'.

I get the error (via console):

Call to undefined function path_to_subtheme() in (path_to_drupal)/drupal57_theme/sites/all/themes/zen-theme/zen_classic/template.php on line 79

when I clicked on the zen theme in the site building>themes

and now the entire site doesn't work due to the error.

James, I just looked at the video. It is talking about Zen 5.x-0.6, so it’s really out-of-date.

Please follow the online instructions: http://drupal.org/node/193318. Also, “zen-theme” is NOT a valid sub-theme name; again, see the online docs.

changing the folder name back to simply 'zen' has fixed it.

Thanks very much for your quick response.

Same here. If you're using Zen theme for Drupal 6 you must replace all
path_to_subtheme()
with
path_to_theme()

Make sure you remove all of them inside pages, blocks and so on.
path_to_subtheme() isn't needed anymore with Drupal 6. Source: http://drupal.org/node/260665#comment-850710