You’re encountering one the following problems: either you are using an old version of i Tunes, you are using an incorrect version of the firmware for your device, or you have gs.re-routed in your hosts file.If you know you’re using the proper i Tunes and i OS version and you’re familiar with editing a hosts file, just throw # in front of the “74.2 gs.apple.com” entry and you’ll be good to go.Try these in order, one of them will certainly fix the ineligible build error: Sometimes a little patience is sufficient to remedy this error message.
Click on i Tunes in the menu bar and then click on “Check for updates.” Once i Tunes is all squared away, it’s time to turn your attention to your i OS device and follow these instructions: Step 1: Connect your i OS device to your computer using an USB cable.
Wait for i Tunes to open and connect to your device.
Before you try though, be sure to turn the i Phone, i Pad, or i Pod touch on and off again, and relaunch i Tunes as well.
If you still run into problems, you may need to flush the DNS cache as well.
If you have no idea what that means, read on and it’ll be explained easily.