Feed issue with undefined get_the_excerpt

I have this error with my feeds:

XML Parsing Error: unclosed CDATA section
Location: http://www.kissmestace.com/thespotlight/feed
Line Number 28, Column 1:

FeedBurner suppor told me this was an error he got (I don’t know where):

Fatal error: Call to undefined function: get_the_excerpt() in /…/kissmestace.com/thespotlight/wp-includes/feed-functi ons.php on line 53

The feed template must say something like this (below), but I can’t find the template. I change the template that has this line on 28, but the “/feed” doesn’t change (as in it still says line 28). I don’t understand why there is no folder “/feed” when I’m logged into FTP. I think I need to find that file.

<?php if (get_settings('rss_use_excerpt')) { ?>
<description><![CDATA[<?php the_excerpt_rss() ?>]]></description>
<?php } else { // use content ?>
<description><?php the_content_rss('', 0, '', get_settings('rss_excerpt_length')) ?></description>
<?php } ?>

I see that this says rss_use_excerpt and the other says get_the_excerpt.

I wish that Windows search actually worked for finding text in html documents, so I can’t find the file. Maybe I need that Google Desktop Search.

The file feed-functions.php has get_the_excerpt and the_excerpt_rss, but not rss_use_excerpt. But it’s not a template file for a feed. Weird. It looks like it’s being defined right there. Where are all the functions defined for Word Press?

function the_excerpt_rss() {
$output = get_the_excerpt(true);
echo apply_filters(‘the_excerpt_rss’, $output);
}

You should read the post at FeedBurner support:
http://forums.feedburner.com/viewtopic.php?p=4301#4301

It also says what I had been doing when the feed stopped working. I didn’t touch anything to do with feeds. I changed templates through the admin and I installed 1 plugin: Custom Post Per Page
http://wordpress.org/support/topic/11211

I also changed entries; I split up a few into more entries than one, and I changed the timestamps to get them in the right order.

All this code and these errors are making my head spin, so I can’t tell if this post is cohesive enough. (I think this text box needs to be larger.)

I think I need to either (A find the file that would define the rss fucntions or B) find the file that is the template for http://kissmestace.com/thespotlight/feed

or maybe even C) change the feed I’m using ??