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.
Having selected Yes to stop running the script I am able to edit text but unable to browse the server to an image etc.