When you’re on the iTunes Store, you might see warnings for a number of reasons, most common and important of which is when you’re about to purchase a paid app. This warning adds an extra layer of protection to prevent purchases due an accidental tap, but also has a checkbox that prevents iTunes from showing that warning again.
If you’ve enabled that option, but want to disable it again, you can tell iTunes to reset all your warnings by following these steps. (Note that you can’t reset warnings individually, so to tell iTunes to alert you before buying paid apps, you’ll have to reset all your warnings.)
Open iTunes and sign in to your account if you haven’t by navigating to Store > Sign in
View your account information by navigating to Store > View Account
Scroll to the bottom and you should see a “Reset” button that says “Reset all warnings for buying and downloading.” Click the button.
I am not sure how many of you would ever want to reset the warnings, but in case you do, this is how you do it.