I'm having the following error when I add a new category or tag on my post_type:

Uncaught TypeError: Cannot read property 'supplemental' of undefined - load-scripts.php:5

I'm having the following error when I add a new category or tag on my post_type:

Uncaught TypeError: Cannot read property 'supplemental' of undefined - load-scripts.php:5

• javascript
• wordpress

• try with a different theme. If it works with a different theme, that means the issue is likely in your functions.php file. If not, re-isntall wordpress and that'll fix it. – alt Commented Dec 5, 2011 at 1:19
• I changed my theme and it worked normal – Anderson Juhasc Commented Dec 5, 2011 at 1:37
• functions.php: jsfiddle/f56c9 – Anderson Juhasc Commented Dec 5, 2011 at 1:46

4 Answers 4

I've just had the same issue, and annoyingly enough it was a whitespace character before the opening PHP tag in a file I included in functions.php. It seems to be invalidating the ajax / json response.

I would suggest looking at any stray whitespaces before and after the tags.

A good idea is to forget the closing ?> tag on functions.php and any included files; this eliminates the chance of a character getting in.

Hope this helps...

Search your theme if you have anywhere session_start() mine problem was " <?php session_start() ... " In file that included into functions.php but session_start() needs to be called before anything else on top of the file..

Check the space before opening <?php in funcions.php or any require files. Make sure there are no space before opening <?php

I can't see anything in /wp-admin/load-scripts.php that would cause that error (fresh install of latest WordPress 3.2.1 here). It could be that someone or something has modified the script which isn't remended, or you're running an outdated version of WordPress, or both.

As it's a core file I'd highly remend reinstalling WordPress, or at least upgrading it. That will overwrite your existing load-scripts.php with a working copy.