We have seen a couple of tickets over the past couple weeks about people with Windows 8 machines not being able to use the 2D viewer. After researching the issue, the developers saw that there were numerous complaints about Java applets not working with the virus scanners. Kaspersky in particular.
After checking with a couple of users who had submitted issues to the help desk, they both found that when they paused Kaspersky they were able to load the viewers. With that in mind, here are the instructions (found here) about how to set Kaspersky to allow Java:
1) Open Kaspersky 2013
2) Click on Settings
3) Click on Application control
4) Click on Applications
5) Look for Oracle America (this is the java and it should be trusted already)
6) Open each item in that folder using double click
7) Under the tab Exclusions check all 5 checkbox and click OK
If you find this doesn't help, then send something in to the helpdesk and we will continue to work on it. But hopefully, this does the trick.