I had the same problem with the Windows 10 desktop app since yesterday. What solved the problem for me was to play a duel using the smartphone app. After that i could also play it under Windows again.
EDIT:
This problem seems to be related to the created deck. In the smartphone app I had to create a new duel deck, although I had created one before in the Windows 10 app.
In another thread(Can't play Duels - #18 by Zero-2869) someone mentioned that clearing your deck and then recreating it also solved the issue.