I Have the blank update tab on my ipad2, ipad 3, and mini. The 2 iPhones and 2 iPod toch 5ths are fine--for now. I have tried everything mentioned on the web to no avail. Reset buttons, network reset, 8.8.8.8 DNs, shut down and wait, change date and wait, change language, change location-- if it's on the web and worked for someone else, I have tried it. Finally I emailed apple. Wrote them what I just posted above. Dude told me to try the very same nonsense I had JUST written I have ALREADY TRIED!! Then he says--if all else fails, call Apple and they will let me know my free and my pay-for-it solutions. Hmpff haven't I already paid for it by buying all these gadgets rather than opting for the much less Android or Kindle-type toys??
Sso I update the long way for now, as someone else mentioned--by spending my time sifting through Purchased and updating 1 at a time...