What does e.body is null mean in jQuery?

I don't understand, FireBug started to show "e.body is null"

)}return this.pushStack(d,a,e.selector...a:a+"px")}}),a.jQuery=a.$=f})(window);

on l开发者_JAVA技巧ine 18 from jquery.min.js using version 1.6.2.

I don't remember what I did yesterday for this error to show up today. Any hint so I can know a little bit more where to search in my code?

It's appear before any ajax request and even before any console.log instruction I ave in my script, but still don't really know where's this error coming from.

Thanks for any help.

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After changing jQuery.min to jQuery, I removed some part of my code and finally I found that:

var documentHeight = $(document).height();

It wasn't in the $(document).ready part of the script... Don't know why the error appear just today, but thanks for the hint, I'll remember it!