I'm guessing you use Google Chrome?
Chrome just released a new build today that blocks flash, and it resets every time you close your browser. So every time you load WGT, you will need to re-enable flash for the site.
Or you can manipulate the settings in Chome by going to
chrome://flags
Search for "flash"
and on "Enable Ephemeral Flash Permissions", change the setting to "disabled"
I can't guarantee how long this hack will work, but it will do the job for now