Can't modify a thread after forming it

I'm running "Curse of Strahd" and their is a section whereca deck is required, I would rather use the on page card drawer. However every time I select the box to turn on. It doesn't work at all.

So you check the box, and you still can't draw a card from the deck you added to the game? Which game?

Thats correct it would be this one. http://gamersplane.com/games/340/

I don't see any deck attached to that game.

I attenpt to attach one then the button cimes unselected each time.

No, the game itself, not the thread. To use a deck in a game, you need to create the deck on the game details page. There is no deck, which is why you can't draw any cards. It's possible there's a bug that's keeping the checkbox from showing up as checked, but the core of your problem is you don't have a deck to draw from. See the bottom left of your game's detail page.

Ah I seee, thank you for the help.