Everyone makes a mistake now and again, but when designers do that, it's kind of a big deal. Their work lasts long after they've made their little typos, and suddenly a product is out in the world looking unfinished or weird . Below are 25 off-the-wall errors discovered this month, from unreadable clocks to signs that never should've been put up on the walls. We have quite a few stairwells that would send most of us flailing down a dozen steps. There are a few subtle fails in the mix too, like…