The same thing happens to me on both my personal Windows Vista desktop computer with Firefox 3.0 and my Windows 8 laptop with Internet Explorer 9. The difference is on the Vista, it stays that way but on the Windows 8, it loads after waiting a few minutes. Does it stay for you, too, or does the actual game load eventually?
I'm pretty sure it's natural for it to be blank the first few minutes (to start up), but should start eventually. I'm pretty sure it also depends on which browser you use (newer ones have a better chance of working.)
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