Windows users:

1- Delete the desktop shortcut icon for ALL UWorld applications you may have (even unrelated ones, doing this will NOT result in loss of any of your previous test/performance data)
2- Click on the Start menu and go to the Control Panel (if you are unable to locate the Control Panel, type "Control Panel" into the search bar)
3- Select "Large icons" in the 'View by:' drop-down box shown at the near top of the control panel (right hand-side)
4- Double click on the Java icon
5.- Under 'General' Tab locate, 'Temporary Internet Files' sub-section and click 'Settings' > 'Delete Files'. Make sure ALL boxes are checked and Click 'OK'
6- Under 'General' Tab locate, 'Network Settings' sub-section and click 'Network Settings...'
In the resulting dialog box, select 'Direct Connection' and press OK
7- Click OK once again and close the Java control panel
8- Login to your account and follow the appropriate link to launch the software