Puffin access
For those for whom the app isn't working right, there is a browser that still supports Flash and will continue to do so: Puffin. Mind you, it's not a free browser, but there is a one month free trial. It should work on Windows, Mac, Android, and iOS.
The great news that I just got is that the game is available for Puffin again (and Puffin alone! other browsers are excluded!). To access it, go to the old address (click "Play" on the game in your profile) and it should take you to this window:
Following the link at the bottom of this notice will take you to the Puffin-friendly version. The notice is visible only in Puffin. Other browsers will not show the bottom part.
Please, note that this is an unsupported way to access the game! Currently, only the app (Plarium Play) is supported and the Puffin-friendly version may be helpful for those of us who need it, but we have to make it work on our own!
I can try to help anyone who runs into problems, but there is no help beyond that, so please do not ping Support because - again - it's not an official way to play the game.