My training game disappeared. What happened?

Nothing is broken and you lost nothing: Playbox deletes the training game on purpose. It goes as soon as you navigate away from its screens, and a background sweep every 20 minutes removes any training game left untouched for three hours, whatever state it was in, half set up or fully played. So an old link from your history or the back button can land on a game that no longer exists, and you get “The test game is gone. Start the lesson again.”

What to do: open Settings, then Tours, and start the lesson you wanted. Playbox builds a fresh training game right at the stage that lesson needs, so the create game lesson opens an empty form, the results lesson starts from a ready schedule, and the confirmation lesson starts from a played out match. You never rebuild the earlier steps by hand, which is why losing the old one costs you nothing.

Your real games, your rating and your money are untouched, because the training game only ever affects itself.