When playing Rummie I can not do anything either when I can meld a group or not, it won't let me discard a card to move on. me and some friends were playing and could not advance on in the game and got a error message.

Hello,
can you copy the error message you received?

Are you playing on the Windows client or on the Web client?

Otherwise, the game seems to work completely fine for me, so you will need to give more details on what exactly you were doing.