Ok after testing it I see the problem, there is a folder (not sure of the name it just shows up as question marks for me) that was set as the sent folder. That was causing RoundCube to send "null:{"subject":1,"to":1}" as part of the environment variables which a proper browser ignores but causes IE to stop loading any JS causing the rest of the errors. I have the Chinese character set for so I don't think that is the problem, I'm going to guess it is corrupted a folder since it wont open. Its in the folder list, let me know if you can give me anymore information on what that folder is.