Why doesn't js redirect work on google chrome 40?

Question

JavaScript

The crux of the problem:
There is a site yaziki.org - the study of foreign languages. Each lesson has a list of words.
Flipping words occurs without reloading the page. When the words end, a redirect to the next exercise occurs.
On my browsers: Google Chrome/ Opera/ FF - the redirect works fine.
But for some reason, testers constantly have problems with the redirect.
at the moment the redirect is implemented like this:
window.location.href="/study/";
before that it was
document.location.href=.....
It is in version 40 of google chrome that there is no redirect.