Anyone who was affected should connect to i Tunes to complete the update or contact Apple Care for help." Initially when clicking on "update," another error window popped up, saying i Tunes would update the i Phone to i OS 9.3.5, the version of Apple's software that came before i OS 10.In my case, the software update through i Tunes failed.There must be other “fix” to this as well – and if you know any of them, feel free to share via the comment section below.Update September 18th, PM: We have confirmed that hard resetting your device can help you get rid of the “Slide To Upgrade” frozen screen.After going through the download and install process over Wi-Fi, the i Phone showed an error window and indicated you needed to plug it into i Tunes on your computer.Connecting it to the computer brought up another error window that said, "There is a problem with the i Phone 'i Phone' that requires it to be updated or restored." The message indicated you might have been able to fix the problem by updating your phone, but if the update didn't work, you might have had to restore your phone to factory settings, which erases all content and settings.
There’s no specific reason for an i Phone getting stuck in recovery mode in i OS 9 update, however, there are certain reasons which may account for the i Phone stuck in recovery mode.
"We experienced a brief issue with the software update process, affecting a small number of users during the first hour of availability," Apple said in a statement.
"The problem was quickly resolved and we apologize to those customers.
This is one of the most common issues that users face when updating to a new i OS firmware.
The error has occurred when i OS 10 was released and may occur in the latest software update as well.