Q: I’ve been having a weird problem with my passcode field not showing up at all when I type it in on my iPhone lock screen. I know the iPhone is normally supposed to show dashes or dots or something as placeholders when I’m typing in my passcode, but in my case it shows nothing—no blank field, no filled in characters as I type. I’m able to get into my iPhone fine by keying in my passcode, but i just can’t actually what I’m doing or how many digits I’ve entered, which is frustrating since if I hit the wrong button I have to start over entirely.
Any idea why this is happening? I even replaced my iPhone 5 recently and it’s still happening on the new one, so I don’t think it’s a hardware thing.

– Kathryn
A: It seems that there is a somewhat obscure bug in iOS 7 that causes the passcode entry field to be hidden in this manner when certain background wallpapers are used.
While we haven’t figured out the exact formula, it seems that dark, high-contrast wallpapers such as the sort of night cityscape shown above can cause this exact behaviour.
iOS 7 tries to dynamically display text on the lock screen to contrast appropriately with your wallpaper, and in this case it appears to be getting something wrong.
Fortunately, the solution is an easy one in this case. Simply switch to a different, wallpaper with more colour and less contrast and your passcode entry field should reappear.