Here is a list of layout errors from first editions of previous expansions, when I was properly respectful of people's complaints (I do not know of any complaints about these layout errors, in case you're wondering how I managed that). It was a bummer that the cards were so poorly done, and when we did 2E main set and Intrigue we also put in the hours to get this stuff fixed (and fix up wordings too). We didn't have to do this and I couldn't tell why I didn't just take naps instead. It goes on and on; you proofread, provide a list of fixes to the layout guy, then proofread again and somehow have another list, and then another; for example I have 15 versions of the Renaissance kingdom cards (counting post-printing fixes - turns out the frames were too light). This isn't necessarily a complete list of the kinds of mistakes that have occurred - for example there maybe still be ones I don't know about - but hits on the various areas of a card.
- The titles aren't consistent in height, for example Militia is lower than Moneylender.
- Types aren't centered vertically, and aren't always the same horizontally, for example "Action - Attack" is farther left on Militia than on Saboteur. Also the spaces next to the dash are sometimes missing, e.g. Mercenary.
- The font isn't just way smaller than is sensible, it's also inconsistent, with random font changes like the tiny font on Transmute, and in fact almost every card in Seaside uses a different font than usual (compare Cellar and Embargo).
- "+1" sometimes has no space, sometimes one space, sometimes both on the same card, e.g. Caravan. Once in a while it has two spaces, e.g. Nomad Camp.
- Text isn't always vertically centered in the text box, e.g. Workshop, and cards with a dividing line tend not to center on each side of it or do anything nice-looking there, e.g. Moat.
- Normally each line of text is horizontally centered and ragged, but some cards justify the text, e.g. Horse Traders (which also I think is the only card that randomly has some incorrect bold text). Some cards also just randomly have off-center lines, e.g. Monument.
- When a coin symbol shows up in the text, sometimes the lines are spaced apart vertically to be even, but sometimes not, e.g. Pawn.
- The numbers on coins aren't always the same size (compare the $1's on Herbalist and Philosopher's Stone) and are often off-center in some way (e.g. Embargo). They are often too close to the text on one side or the other, e.g. the $4 on Talisman.
- Looking to see if I could find an error in the art, I have only just now noticed that Pearl Diver's art is a couple lines short of the top; compare the bottom of the title banner between Native Village and Pearl Diver. Sadly the 2E version also has this mistake; we didn't catch it and it was never reported. Of course the big one here is, Pathfinding went out with a big chunk of black on one side of the art, that you can think is a tree.
- There are of course artist attribution mistakes too, e.g. all the cards that say Claus Stefan.
- If you thought at least the expansion symbol never had a mistake, I am sorry to tell you that it's too small on the Update Pack versions of Artisan and Bandit. Isn't that weird. The 2E main set versions are fine somehow.
- And hey, we've had the frame be too light. Secret Cave has a lighter frame than the regular duration cards in Seaside etc. (the Night - Duration cards are lighter too, but there you can say, maybe they intended that). I've never seen a complaint there - a playtester noticed it apropos of the Renaissance frames being too light - but I mean I can't rule out that someone was sad. There's also how Necropolis doesn't match the other Shelters for which side is red, but I don't know if that qualifies as a "mistake" or just a "dumb thing."
You can go see this stuff on the wiki, except I didn't see a picture of Artisan or Bandit with a smaller expansion symbol. I have them right here though, it's a thing.
Of course versions in other languages have lots of text mistakes and who knows what layout mistakes.