Yeah, I've seen this too. The ones I've seen so far are cardsic13g and cardsic11. I'm playing on Windows.
Are you saying the issue occurred with those cards or that you've seen them in game normally?
That I've had the same display issue. Those are the cards that aren't displaying, according to the error text (there could be more though). Though I realized later it's "cards/c11", the text is so tiny I mistook the slash for a lowercase i lol
