Syntax error: <!DOCTYPE html> (line 1) in Firebug

Question

Firebug is complaining about a error in <!DOCTYPE html>, but the HTML source is passing without problems the HTML W3C validator.

Do you have any idea? Sorry, I can't share the source code.

Did you change the Document type, or is it the standard one used by Drupal? Which error does Firebug report?
I changed in the theme page.tpl.php to use the HTML 5 doctype, but if I put the default Drupal Doctype also is throwing the error. There is no more information from Firebug than what it's in the title of the question.

corbacho · Accepted Answer · 2011-05-05 10:47:29Z

The reason was a failed loaded javascript file.
I use the following code to add a JavaScript file:

drupal_add_js($p . '/slider.js','module','footer');

So the following HTML was added in the footer of the page:

<script type="text/javascript" src="/sites/default/modules/custom/slider/slider.js?G"></script>

At some point I renamed the file slider.js, so it stopped being loaded, and this is the reason behind the Firebug error.

In the "Net" tab, Firebug was not showing any error; it was showing just a "301 Moved Permanently" next to the slider.js file.

The filename was already slider.js. Do you mean you moved the file to another directory?

nonsenz · Answer 2 · 2011-05-05 08:21:51Z

Maybe this is your Problem, too: http://blog.rki-home.de/2008/10/22/firebug-syntax-error-und-doctype/ It's german so here what it says in short:

Do you have a script tag with empty src?
Do you link a html-file with script src anywhere?
Do you use some mod_rewrite rules wich could result in returning html instead of the real js-source?

When FireBug states an error, i would think it's always an JS-Error. So FB tries to parse html as js.

Thanks nonsenz for the hints, I found the reason finally and put it as an answer.

2 Answers