Just bought a used Galaxy S 3. When I went into settings and checked for an update the above message shows every time.
What up with that?
Is the phone rooted? If it rooted then chances are the Fwupgrade is frozen or deleted therefore causing the error you are getting... The Fwupgrade (along with another.) are what allow the phone to actually update and check for update.... If those are missing or not able to be opened it will cause that error to show... If the phone is NOT rooted let me know and I will walk you through the steps to "reset" those 2 options and see if that does the trick.