On my 4th match of today duel decks run the game crashed on the beginning of the match.
Screen almost black. I can open pause menu, but no objective. Can’t leave, have to force close the app.
A teammate reported same issues.
Just got this myself on my first match, fighting another Nissa? I though this was dueling againts the eldrazi?
Me also. Had to quit the match and lose a charge. 
Me also. Had to quit the match and lose a charge.
Submit a ticket… I’m only seeing this happen to nissa… this is going to change the outcome of the duel.
I play TED. Happen to me twice yet. Why now? Not happen in beta2 and beta1 with hundred matches.
Btw. Second crash was TED vs. Nissa. So, not only false opponent issue.
This bug has been there since the first Beta run of the event. You sometimes get matched up against the same side as you, which immediately crashes the game when you try to play the match.
The bug sometimes happens when a regular match starts as well, although much less frequently.