I also have the same issue / warning with directory structure when I click on Browse Server having installed the new security fix.
In addition if it helps, having sign in to the CMS OK, select a file from the home page or directly on the website, if I then click on edit I get the following Windows Internet Explorer warning:
Stop running this script?
A script on this page is causing internet explorer to run slowly. If it continues to run, your computer might become unresponsive.
Yes NO
Having selected Yes to stop running the script I am able to edit text but unable to browse the server to an image etc.