After setting up a new WP site did I want to burn the feed at feedburner only to find out it did not validate. As the new site basically is set up like my old one did I test that feed as well. It didn't validate either.
This is the error on validating:
This feed does not validate.
line 1, column 1: Blank line before XML declaration [help]
So, I checked the help page at feedburner, which states:
Blank line before XML declaration (WordPress)
If an XML declaration (<?xml ... ?>) appears in your feed, it must be the first thing in the feed, before any whitespace.
Unfortunately, with WordPress it seems all too easy for a plugin, a theme, or for your configuration file to contain a blank line. Further compounding this problem, some — but not all — feed readers compensate for this common error, allowing the error to go undetected for quite a while.
* Check your wp-rss2.php and wp-atom.php files for blank lines outside of <? and ?> bracketed sections.
* Check your wp-config.php file for blank lines outside of <? and ?> bracketed sections.
* Check your theme's functions.php file for blank lines outside of <? and ?> bracketed sections.
* One by one, disable plugins and revalidate until you isolate the one causing the problem.
Not clear? Disagree?
I checked every file mentioned and then some. Instead of checking each plugin did I simply turn them all off. I have more than 30 in use and did not want to go through turning each of them off if I only were to find that they weren't the problem either. Which they apparently weren't as the problem also was present after turning them all off.
They question is what can now do? As a small test did I make a clean 2.2.1 install on another domain and check the feed and that validates fine. Can the plugins be the problem although it is also present when I turn them off?
I am really desperate as I need the new site up and running by Wednesday and this damn problem have stolen most of my Sunday already.
All suggestions are welcome. The more constructive the better...