Invalid key. Auto-translated

Heroes 6 has been gathering dust for a long time. I decided to play it again. I logged into Uplay and downloaded it. When I launch the game, it gives me this message: Invalid key. There is, of course, no connection to Conflux. I installed the game from the disc, and it's still the same story. Also, I have 2 accounts with Heroes, and the same thing happens on the other one. Can anyone help me and explain what the reason is?