RSS issues – 500 errors

I’ve unsuccessfully tried a number of suggested fixes found on the forums – none seem to apply specifically.

I’m running WP 2.0.6. I’ve made the suggested changes to wp-includes/functions.php.

I’m using this Ordered list plugin for Feedburner feed redirection (currently deactivated): https://orderedlist.com/wordpress-plugins/feedburner-plugin/

The only .htaccess changes I’m using are at the root level and serve to redirect domain.com to https://www.domain.com.

I’ve tried deactivating and reactivating the plugin, reuploading the various feed php files and I’ve tried some changes to .htaccess. I haven’t be able to resolve this problem.

These feeds generate fine:
index.php/feed/rss/
index.php/feed/rdf/

These don’t work at all (generate 500 errors):
index.php/feed/
index.php/feed/atom/

At this point, I just want to get the feeds working properly, and then I want to redirect them to feedburner.

Any help would be most appreciated…

Thanks,
Dave