Error installing iOS 9 appeared immediately after iOS release 9 by the Apple company, saying the following: Software update failed. There was an error downloading iOS.
As you probably already imagined, the error is based on the fact that Apple's servers are much too congested to deal with the very large number of people trying to download iOS 9 at the moment and that you cannot do anything.
The only solution to install iOS 9 right now is to follow the installation procedure through iTunes, as it is described in the article in which I told you how to install iOS 9.
It was normal for a problem like this to happen considering that millions or maybe even tens of millions of people are trying to download iOS 9 from Apple's servers.
