I'm trying to open https://es.wikipedia.org/w/index.php?title=Primera_B_(Argentina)&veaction=edit&vesection=6 in IE 11, and it just hangs when the bar is almost 2/3 full (I'm not logged in there, if it helps, and trying to edit the entire article instead gives the same result).
@Elitre: Sure the problem happening on other articles is not T103498 instead which might block retesting the problem covered in this task? Here when not being logged in on Firefox 38 on Linux (not IE) and going to the link above I don't see the progress bar going away either after 2/3. And the browser console says "TypeError: $.escapeRE is not a function" which sounds a lot like T103498.
es.wiki have a bug in their common.js (using document.attachEvent which doesn't exist in IE11) which is probably the cause https://es.wikipedia.org/wiki/MediaWiki_discusi%C3%B3n:Common.js#URGENT:_Exceptions_thrown_in_IE11