Are you seeing the following issue?
Please ensure within File > Preferences > Advanced that "Force use of Embedded Mozilla Browser" is disabled. The embedded browser is not needed as Internet Explorer 10 comes with Windows 8 as default.
A small minority of Windows 7 users are experiencing this issue, we are working hard to identify the conditions that cause this in a future release. If you find you are experiencing this issue please contact firstname.lastname@example.org and you can be added to a contact list which will be notified once a fix has been released, alternatively this forum article will be updated upon the release of fix if you wish to subscribe.