Custom cards showing up in deck editor, but not in duels

[terminatorskull]

I've been watching/reading a few tutorials over making custom cards, and ran into an issue. I'm able to see the image/description of my custom cards in the deck editor just fine, but whenever I start a duel it gives me the "invalid deck" error. If i start a local game with myself using 2 games open at once to duel and turn off the "check deck" feature I can play, but I only have 39 cards in my deck. Wondering if there's some step I'm forgetting or if I'm using the wrong directories,