I have had an iPhone 6plus for 7 months. No troubles. Before I left the country I contacted Verizon and had them add an international plan for all of the countries I was visiting. I arrived today and when I turned on my phone I got the following message "Activation Required". It then asked for my 4 digit code. When I put in my 4 digit code to unlock phone it prompts me to choose a wi-if network. When I try to connect to a wireless network I get
"it may take a few minutes to activate your iPhone." And then "your iPhone cannot be activated because the activation server cannot be reached. Try connecting your iPhone to activate it, or try again in a couple of minutes. If this problem persists contact Apple support at Apple.com/support".
It also tells me to activate using iTunes but I don't have a computer only my iPad. I also tried to reach Apple Support but all I could get online was to return to a service center.
I cannot MAKE CALLS, get settings, email. I can not go anywhere past the page that says the phone cannot be activated. Verizon was supposed to add international coverage effective 8/20. I called on 8/21 and they said it was activated.
It worked fine before we left the U.S. I followed the instructions that the lady from Verizon gave me. She told me immediately before I left the U.S. to turn off the phone and then turn it on again and then off before the plane took off.
Verizon added a FEATURE that afords prefered pricing, not SERVICE. Verizon does not offer service outside the USA. At this point, the device may only return to normal once it is connected to the network here is the USA.
To have service you may want to look into getting a sim card from a local provider for the time you are there.
Your device should be fine when you get it connected back in the usa.