"I can't activate my iPhone 5s after upgrading to iOS 10. It says that the activation server is down , My iTunes (latest version) won't recognize the iPhone. I have tried hard reset, and I have also tried using Wi-Fi and LTE. All of these doesn't work at all. Any help?"
If you are encountering the same activation issue, please comforting firstly. "Can't Activate iPhone after iOS 10 update" actually is a very common error when iOS users upgrades their iPhone X/8/7/SE/6s/6/5s/5 into iOS 10. To fix can't activate iPhone/iPad problem after iOS 11/10.3/10.2/10.1/10 update, here are 6 simple ways for you to consider.
Once the activation error happens, the simplest way is to wait for a moment before try again. But this can be considered only when the error is generated from Apple's activation server.
Another easiest solution to fix activation errors is to reboot your iPhone X/7/SE/6s/6/5s/5, which is almost the usual way to remove many kinds of accident issues.
How to restart:
If this solution still can't activate your iPhone/iPad/iPod touch after installing iOS 10/10.3 , move to the next step.
SIM card is also related to the activation issues. If you haven't installed one SIM card in the SIM try, you will not able to enjoy the exact service from the cellular carrier. Right now insert any valid SIM card to see if this will walk through the activation bugs.
In some cases, WiFi network connectivity plays an important role if you want to reach Apple's activation servers via an internet connection. Hence, please check if your WiFi network is reliable.
What to do if can't activate iphone after updating to iOS10/10.3 when you have tried on the above tips? If you don't have great Wi-Fi networks and cellular service at the moment, please move to connect your iPhone/iPad/iPod on a trusted computer and activate your iPhone through iTunes that has an activation mechanism built into it to reach Apple's activation servers directly without an internet connection.
If the annoying iOS activation bug still exists, you can also try to restore your iPhone with iTunes. Finish the steps below to activate your iPhone/iPad:
Hopefully, if the aforementioned ways fail to help you, here is a paid program you can try to reactivate your iOS 11/10 device again. iCareFone is an all-in-one tool to fix all iOS problems and tuneup iPhone/iPad/iPod. It can not only fix your iDevice into normal but also make them run faster by cleaning unwanted junk files. If you have other recommendations, please share with us.