With over-the-air updates for iOS updates/upgrades have made updating your iPhone/iPad easier. Whenever there's a new update, all you have to do is head over to Settings → General → Software Update and install the update.
But as is the case with every new update that's pushed for iOS (iOS 9 recently), there's a huge flux of traffic as hundreds of thousands of people try to access the update files at once. Apple devised a new way to address this. When you get to the software update page on your iPhone and tap on the “download” or “update” button, you'll see “Update requested…” which then downloads the update. But sometimes, it gets stuck there and doesn't download the update file at all.
While there's no specific fix to address this issue, you can try a couple of things to get out of it. When you find that the update is stuck at “Update requested…” and you can't do anything beyond this point, you should resort to doing any of these solutions:
#1. Network Reset
One of the first things you should make sure of is a stable network. If you're on cellular or spotty Wi-fi, there can be problems when your iPhone tries to contact Apple's servers to download the update.
Once you are stuck at “Update Requested…”, it's best to turn off the networks on your iPhone and reconnect it. If you are on a 3G or LTE data network, try to switch to a stable Wi-Fi service before updating.
#2. Hard Reset
If network is not the issue, you can try doing a hard-reset to get the update working again. To hard-reset your iPhone/iPad:
- Press and hold the Power and Home button till the screen goes black
- Now, press the Power button to boot the iPhone/iPad
After you hard-reset, check the Software Update page again. Either the “Update requested” changes to downloading or you get to start all over again to download and install the update.
If you see the “Update requested” for hours after you've initiated the update, and all the above methods haven't fixed it, there's probably only one way of getting the update done – via iTunes. Surely, this beats the very purpose of an OTA (simplicity) but given that the iPhone is stuck in the update, you might want to switch to the old method.
Connect your iPhone to the PC/Mac, fire up iTunes and from the Summary tab, click on Update. In most cases, iTunes will automatically show a pop-up that says there's an update for your iPhone/iPad.
Of late, many users are reporting that iOS 9 update stuck At “Slide to Upgrade” screen issue. Here is a fix.