Here's my situation, which I can't tell is the same as is being debated here.
Itunes 12.3.2
Iphone 6+ v9.2.1
Iphone is acting laggy so I want to restore it. I plug it into my MBP and hit restore. iTunes says there's a new version, 9.2.1, that must be downloaded and installed before I can restore the phone. Yet when I try to download it, after about 15 minutes it states that the download failed (forget the error reason).
So, iTunes says I need to upgrade to 9.2.1, but cannot successfully do so thereby preventing me from doing a restore on my phone. Thoughts other than doing a factory reset on the phone and then hoping "restore from backup" isn't similarly blocked by this failure to download issue?
Thanks
Perry