That is to say, I can load the game, but the "add bot" button seems to be missing, so I can't start the game. Has there been a change?
Works fine for me on Windows Firefox for e.g. game 85953012
What device, OS and browser are you using?
Hmm, I see the problem. The game I was trying to load is a 1-player game apparently. It's game #66318559 in the card bug list. I didn't know that 1-player games existed and I don't know how to start them. When I try to start it, it just says "not enough players".
Ah, searching the forums I found this old thread: http://forum.shuffleit.nl/index.php?topic=1575.msg5226#msg5226
And I was able to solve it. Thanks.