"jQuery is undefined" in IE

I'm trying to recreate it but I can't on a default install (http://drupalstaging.com/pixture2/)

Do you have a link to your installation? Any other JS stuff going on etc?

I'll read those other threads, any thing else you might think might be a contributing factor?

Thanks for the feedback, this may be helpful for other users. I appreciate the time you took to come back and post about this.

I am having the same issue. In my case, the problem seems to be that Drupal does not forward the js file to the browser, but I do not know how to fix it.

This is what I get in Explorer 8.

Message: 'jQuery' is undefined
Line: 30
Char: 1
Code: 0
URI: http://localhost/Excel

When I look on line 30, it says:

<!--//--><![CDATA[//><!--
jQuery.extend(Drupal.settings, { "basePath": "/" });
//--><!]]>

This is how the jquery.js file is called in the web page code

<script type="text/javascript" src="/sites/all/modules/jquery_update/replace/jquery.js?o"></script>

When I attempt to go to the http://localhost/sites/all/modules/jquery_update/replace/jquery.js page, I get error 403. My filesystem download method is set to private (I am not sure if that relates to it). Would anyone have any idea how to fix this, please? I am runnind Drupal 6.19.

Shifting this over to the Jquery Update queue, see if you can get some feedback there - sorry, I can't answer your question directly.

I don't know which version you are using so I am guessing :)

Thanks. I am using jQuery Update 6.x-1.1 and jQuery 1.2.6.

I have a new finding. When the jQuery Update 6.x-1.1 module is disabled, jQuery is referenced as follows:

 <script type="text/javascript" src="/misc/jquery.js?o"></script>

and no error msg appears. Then, when the jQuery Update 6.x-1.1 module is enabled, jQuery is referenced as follows:

<script type="text/javascript" src="/sites/all/modules/jquery_update/replace/jquery.js?o"></script>

and I get the "jQuery is undefined" error message. I am not sure what to do. Should I copy the /sites/all/modules/jquery_update/replace/jquery.js file over the /misc/jquery.js file, disable the jquery update module and leave it that way? (Sorry for a stupid question, do I need jquery at all? I installed the jquery update module just because I saw a message on the website status page that I should do it, but I do not see any difference in the site functionality (except the error message) with or without the module.)

I'm seeing this as well. I will investigate and see if I can find the source.

Also, I'm using 6.x-2.0-alpha1 so it doesn't just affect 6.x-1.1

Also, this seems to only affect IE versions less than 8.

My issue seems to have been solved by using the regular version of the jquery file instead of the minified version.

Not ideal but if it fixes the problem it's not the end of the world.

Scratch that last one, it actually seems to have been fixed by turning off javascript aggregation (regardless of using minified or development jQuery), which is definitely not ideal but at least for now it is working for me.

Put jquery script tags before any .js script tags that use jquery. This will fix the IE error. Although Firefox does not complain - the included js files fail gracefully.

Thanks for the tip.
But if everything comes from the $scripts variable and drupal_add_js() doesn't have a weight option in drupal 6 how can you make sure (I would assume drupals js system would already handle adding jquery first for within the $scripts variable).
I'll also double check for any scripts outside of the $scripts variable.

had same issue with version 6.x-1.1, solved by suggestion of Agileware: disabled the javascript aggregation.
unfortunately Drupal is not very friendlu with jQuery.

I'm having this same problem. Problem is if I disable the aggregation, my page won't load at all in ie8 and below. I think that has to do with IE's script limit, correct?

i am also experiencing this kind of problem in IE when the highslide js functionality is enabled. works great in FF and chrome but unfortunately in IE, it doesn't work at all.. the js error 'jQuery' is undefined still appears. I think there is some conflict with the jQuery and highslide.js in IE. But mysteriously, it doesn't have any problem on other browsers except IE. any ideas?

I had this problem. My problem was how I was calling the JS.

Adding the JS to my theme like this:

drupal_add_js('sites/all/themes/mytheme/facetaccordians.js', 'file');

Worked fine. However I wanted it to be conditional so modern browsers didn't have to have an extra JS file. The only way I managed to get this was adding the stylesheet straight into the html.php file.

The following was also suggested somewhere, however this caused the undefined problem.

$ie6minheight = array(
  '#tag' => 'script',
  '#attributes' => array( // Set up an array of attributes inside the tag
    'type' => "text/javascript",
    'src' => "http://mysite/sites/all/themes/mytheme/ie6minheight.js",
  ),
  '#prefix' => '<!--[if lte IE 7]>',
  '#suffix' => '</script><![endif]-->', 
);
drupal_add_html_head($ie6minheight, 'ie6minheight');

Drupal 6 reached EOL (end-of-life) on February 24, 2016.