On some iOS devices, “Sign in to iCloud” message keeps popping up every few seconds/minutes, breaking the workflow. It's annoying to say the least and the frequency of the popup is so bad that it doesn't even let you fix it on the iPhone/iPad. (Here is how to fix iPhone stuck in sign in to iCloud popup loop in iOS 8.)
After dabbling in this trouble much, it looks very certainly that the problem is with Wi-fi. If you are not connected to Wi-fi, if your iOS device has trouble latching onto a network or if there's something else blocking your device from connecting to a Wi-fi network, this “Sign in to iCloud” loop will happen.
Fixing this requires that you connect your iPhone/iPad to a Wi-fi network. That means you head over to Settings → Wi-fi and then join a network and enter the password for the network. The only problem is that the popup message prevents you from doing this simple activity. Every time the popup shows up, it blocks the workflow, prevents you from doing anything in the background until you dismiss the popul by entering a password.
There are some ways to fix this. The trick, it turns out, is to somehow get the iPhone some breathing space and time so it can latch on to a Wi-fi network before the popup reappears.
#1. Hard Reset + Wi-fi Setting
Hard reset is when you press and hold the home button and power button till the screen goes blank. Then, press the power button to boot the iPhone. When you do a hard reset, and when the iPhone reboots, the iPhone takes some time to initialize things before thinking about iCloud.
This time can be used to connect the iPhone to a Wi-fi network. So when the iPhone boots up after the hard reset, the first thing you do is head over to Settings → Wi-fi and join a network.
#2. iTunes Backup + Sync
If hard-reset doesn't work, you might have to seek the help of iTunes on your PC/Mac. To do this:
- Connect your iPhone to the computer and fire up iTunes
- From the side-bar, select your iPhone. Right-click on it and click Back up Now…
- Ignore the “Sign in to iCloud” popup (or dismiss it)
- When the iPhone is being backed up, the popup will not come up on the screen. Use this time to join a Wi-fi network.
- After the backup, disconnect and go to Settings → iCloud and then re-sign-in to your iCloud account. (Or if the popup shows up, enter the password in the same)
In the event that even the previous method didn't work, your only option is to restore. This is mostly because the only other time when you can connect to a Wi-fi network without a problem is when you are setting up your device from a fresh restore.
When you restore and set up your iPhone as new, you will be asked to join a Wi-fi network. And then you can sign in to iCloud without a popup loop killing your iPhone.
A restore is also your only available option if there is no Wi-fi.