Problem: Was trying to update my iPad to the latest IOS version using iTunes (had to do this in recover/restore mode because it got locked out). After the download if the IOS, it started unpacking and then gave me the following error:
“This device isn’t eligible for the request build”
I went to Apple’s site and found the following article. I tried checking the hosts file, TCP/IP filter and restoring from another computer and all had failed. I also was told to check and make sure iTunes was the latest version without any luck.
Solution: All the articled said for me to check the iTunes version but none told me to check the OS version. I used my Macbook Air that had El Capitan installed and I was able to restore/update my ipad. So if you still use your Mac to manage/update your iPad, make sure you have the latest version to ensure a successful update.