Board Thread:Questions and Answers/@comment-28262336-20160505134949/@comment-34263638-20180502111138

I was going to ask you to check whether the duels even attempted a tiny bit before failing or not but since you said you already tried many times and you said your facebook is working. I would assume that the duels load for like a fraction of a second before it failed. The only solution I know is to keep trying. It may take more than 10 tries for it to work.

If it doesn't work, you won't really need the duels to finish Act VI and the Interlude anyway. (There is also Act VIII: Chapters 1-3 but you won't be experiencing them on Windows).