Game #174451326. Forgot to check which server.
Enlightenment was active. Opponent played Warlord on their turn, so now I am limited to the number of coppers I can play. I played 2 coppers (as actions because of Enlightenment), then played some other cards, then I could no longer play my remaining coppers. The Autoplay Treasures button also failed since I wasn't allowed to play those coppers, so I had to resign the game.
Thanks for the report, Max!
This is indeed a problem, as there is no way to continue your turn (there should be a button to end your buy phase, but there isn't).
I'll forward this. Thanks again,
Ingix