I will warn you now this might not work for you but it is what worked for me.
If you are locked out of duels with this error message with a 0 game duels deck.
There was an error starting your game. Please wait a few minutes and try again
The work around solution I found is to dust all copies of a card in the deck. For me I dusted both copies of a common card in my duels deck. Which forced the game to let me rebuild my duels deck. After I changed out that one card in the deck I immediately queued and was able to play duels again.
I would first recommend attempting to queue then when the error message pops up take a screenshot. Then take the screenshot and contact customer support for a dust refund due to this game bug.
I was locked out of duels for over a month due to this bug I tried queueing many times and always had that error message pop up. Just today the idea of dusting a card to force a deck re-build came to me. But now I am out 80 dust due to a game bug until my ticket goes through.