When I try to join the game I'm hosting, it loads but it is stuck on the "Your game will begin shortly" screen and this shows up in Dream Daemon.

runtime error: bad icon operation
proc name: New (/icon/New)
usr: null
src: /icon (/icon)
call stack:
/icon (/icon): New('', "Real Card Game Back", null, null, null)
the mob (/mob): ()
It's a runtime error. The guy that wrote the game you are trying to play did a bonehead.

More specifically, it's trying to perform an icon operation on a graphic that doesn't exist or is invalid.
Thank you Ter13.