Can't "approve this phone" after iOS 10
Dear tubedogg & Gabriel,
As Gabriel pointed out, this problem is NOT related to iCloud Keychain, but actually to Two-Factor Authentication. Unfortunately, this problem has not been solved even by iOS 10.0.2 released on Sep. 23rd yet. If you automatically turned on the authentication during your update to iOS 10x, here is the solution.
STEP 1: When you update the iOS, skip "approve the phone" by pushing the button of Cancel. You can retry it later.
STEP 2: Complete the iOS update by following the instruction.
STEP 3: Make sure that your Two-Factor Authentication is ON at this moment by either of the following options: Option A) Read a notification email from Apple. Option B) On your iPhone, go to [Settings] --> [iCloud] --> tap your profile of Apple ID --> Password & Security --> Two-Factor Authentication
STEP 4: Turn OFF the Two-Factor Authentication. During this process, you will be required to reset your Apple ID (iTunes & iCloud) password. But no worries, no date will be deleted. If you received the notification email about the Authentication, you will find a link of "turning off the Authentication" in the email.
STEP 5: After completing the Authentication OFF, retry "approve the phone" by going to [Settings] --> the red flag. Without doing anything, your iPhone will be automatically and immediately approved. All set.
You can get the Two-Factor Authentication back ON anytime later if you wish.
Hope this helps.
(This applies only to iCloud Keychain. All other iCloud data will be transferred even if you choose to skip the approval process.)
Does your husband have an iPad? If so, accept the request from that device and try again.
Otherwise…
If you can't access any of your other devices that are using iCloud Keychain, you can still set up iCloud Keychain on another device if you have these items:
- Your iCloud Security Code
- The device that is using the SMS-capable phone number you provided when you first set up iCloud Keychain. A verification code is sent via SMS to this phone number. If you can't access this number, contact Apple Support, who can verify your identity, so that you can complete setup on your new device.
After you complete the setup, your iCloud Keychain will be pushed from the cloud to the new device. If you use two-factor authentication with your Apple ID, enter your password and the six-digit verification code that's automatically displayed on your trusted devices and authorize the new device. Then turn on iCloud Keychain.
Source: https://support.apple.com/kb/HT204085