The phone app seems to be the cause of some user woes too. When you are in the Phone app settings, the app may suddenly crash or freeze which means that you will not be able to make any changes at all. Restarting or resetting the phone seems to be of no reprieve, but some users have been able to link the problem with Exchange contacts.

Solution 1: Update your phone’s software

Those who updated to iOS 10.2.1 found that the problem disappeared. So if you haven’t already, then you must try to update your phone’s software. It is best to keep you phone updated at all times.

• Go to Settings
• Then tap on General
• Go to Software Updates and if an update is available then install it

Solution 2: Switch off Exchange Contacts

Some found that the problem was stemmed in exchange accounts so switching it off did the trick.

• Head into the Settings menu of the phone
• Tap on Contacts
• Tap on Accounts
• Go to Exchange Accounts
• Toggle off the slider next to Contacts

This should solve the problem with the Phone app.