FWIW - there was a JAVA update in the last few days so you may want to clear your Java cache.
At times players that use the same browser and/or OS have issues because the browser/OS updated.
Of course if WGT needs to make changes to accommodate the updated browser or OS it may take a few days before WGT is able to discover what changes will work with the updated browser or OS.
Years ago I wrote web page code and only tested my code in the most used browsers and OS releases.
Today there are a lot more browsers out there so when one of the browsers updates and a web site has to make changes to accommodate that update they also have to make sure those changes necessary for the 1 updated browser don't screw up performance on one or several of the other browsers.
Set up your computer so it notifies you before browser, Flash Player, Java, or OS updates are loaded on your machine.