Re: How to make friends on IOS?

You might not have it enabled. Try this: settings, general, restrictions - they should be off. Or For Game Center, the green button there to allow it? Also look at your profile for Game Center. Have you set it up? -> settings, Game Center, Game Center profile. (Been awhile since I did this but I believe I had to put this info into it.) Another thing, in the settings and Game Center, do you also have allow invites on? 

If all of this is set, then try a hard reset. Hold down the home button and power button until the device completely powers off. Then when you restart it, it should fix itself.

If none of this works, post back.