iPhone 7/Plus iMessages does not activate after a fresh install

[AMSOS]

My iPhone 7 was working fine until I decided to upgrade to iOS 12.1.2. The update went fine and I erased the phone and data afterwards to get a fresh install.
However, my iMessage and FaceTime on the phone are no longer working.
Basically, I keep getting messages that iMessage is unable to activate.
When I go to "Send and receive" I only see my Apple ID email address and no phone number is displayed.
What can I do to reactivate iMessages now?
Please help.
Thanks!

 

[BugeyeSTI]

What was the purpose of the fresh install if the phone was working fine? I'd say restore the phone using iTunes again if the problem persists.. I only do fresh install if I have problems that can't be fixed by normal means or a brand new device..

 

[newellj]

Funny you should mention that. My 7 just quit iMessage and won't reactivate. HNY from Apple? (Just kidding.)

 

[I7guy]

My iPhone 7 was working fine until I decided to upgrade to iOS 12.1.2. The update went fine and I erased the phone and data afterwards to get a fresh install.
However, my iMessage and FaceTime on the phone are no longer working.
Basically, I keep getting messages that iMessage is unable to activate.
When I go to "Send and receive" I only see my Apple ID email address and no phone number is displayed.
What can I do to reactivate iMessages now?
Please help.
Thanks!

Try turning airplane mode off and on. Also try turning cellular data off and on. Jiggering these settings might help.

 

[AMSOS]

What was the purpose of the fresh install if the phone was working fine? I'd say restore the phone using iTunes again if the problem persists.. I only do fresh install if I have problems that can't be fixed by normal means or a brand new device..

Well, over the years I've found it a good practice to wipe the phone and use a fresh install. I've never had those low battery backup and other such issues that people complain about after a regular update.
Also helps clear out the phone of accumulated junk that admittedly my phone does not have a lot of.
I wiped the phone again with the same problem. And then magically it was able to detect and show my phone number on both iMessage and FaceTime! I am guessing it had to do with the fact that I put some money on my pre-paid connection.
Thanks!
[doublepost=1546449446][/doublepost]

Try turning airplane mode off and on. Also try turning cellular data off and on. Jiggering these settings might help.

I did all of those and nothing worked.
Eventually, I think it could have been the simple fact that I added some balance to my pre-paid phone and after a few hours it recognised my phone number.
Though I can't be sure...
While on the subject, do you not wipe the phone after upgrading to a new iOS version? Do you think it's a redundant practice as BugeyeSTI suggests above?
I may not wipe the phone at all in the future...

 

[eyoungren]

Well, over the years I've found it a good practice to wipe the phone and use a fresh install. I've never had those low battery backup and other such issues that people complain about after a regular update.
Also helps clear out the phone of accumulated junk that admittedly my phone does not have a lot of.
I wiped the phone again with the same problem. And then magically it was able to detect and show my phone number on both iMessage and FaceTime! I am guessing it had to do with the fact that I put some money on my pre-paid connection.

I have to wonder about this sometimes.

My current iPhone 6s+ is using the same 'profile' it has used since December 2011 when I set up a 3GS I got from my sister. That was passed on to a 5, to a 6+, and to my 6s+ with updates along the way from iOS 5 to iOS 9.

The profile even forked back to my 5 and an iPad Air 2 which then got passed to my iPad 6th Gen.

I have an iPhone 4 that is running off a 2014 iOS 6 backup of this profile.

And I have been jailbroken from iOS 5 to iOS 9 on these phones and iOS 10 on my 5.

I've never had any issues in the last 7 years.

It makes me wonder what people do with their phones that corrupts data so bad that you have to periodically restore as new.

 

[bbrks]

It makes me wonder what people do with their phones that corrupts data so bad that you have to periodically restore as new.

Jailbreak maybe

To answer OP's question....it could also be a problem with your carrier. That happens a lot, at least here in Europe...

 

[eyoungren]

Jailbreak maybe

Possibly. Many people who jailbreak don't think too hard about it.

For me, I execute a plan every time I need to upgrade or switch devices. A backup, DFU restore/upgrade, then a restore from backup. Never been an issue.