iOS 15.4 - iMessage won't active. Error message - "An error occurred during activation."

jamesbfg wrote:

• Hi all, I've just updated to iOS 15.4 and my iMessage has stopped working. I didn't turn it off but it stopped functioning on my iPhone (still works on my Mac).

I have tried

Restarting (hard reset) iPhone with iMessage off and then turning it on again.

• Turning iMessage on and off again, but I get an error message - "An error occurred during activation."

• I have tired turning on/off Airplane mode.

None of these have worked. A little worried it's a bug in iOS 15.4 as I didn't have any issues before. Any ideas greatly appreciated.

Follow ALL steps here If you can’t turn on or sign in to iMessage or FaceTime - Apple Support

Settings, Messages, Turn off iMessage

Settings, Face Time, Turn off Face Time

Restart the phone.

Settings, Messages, Turn on iMessage, SMS, MMS

Settings, Face Time, Turn on Face Time

Problem activating iMessage

See If you can't turn on or sign in to iMessage or FaceTime – Apple Support (UK)

I think i may have been able to solve it. Are you all using an E-Sim only in your device?

I was trying to troubleshoot this issue (spend a night without cell phone service.)

But i was able to get it working again.

1. Have another phone handy cause you will need it to contact you provider (t-mobile in my case)
2. Make sure that you have access to wifi cause you will need it to gain service back.
3. I removed the cellular plan from my account. so that my phone lost service completely. and no service was associated to my phone.
4. Called tmobile from the other phone and asked them re input the EID in their system on their end.
5. waited a few moments and went to add the cellular plan back to my account and then everything starting filling back in.
6. went to reactivate imessage and facetime and it worked with no issue.

Seems like that fixed the problem.

I'm not sure if the people having this problem are using esim or not but this seems to have done the trick and i am able to get and receive imessage and facetime calls again.

I think i may have been able to solve it. Are you all using an E-Sim only in your device?

I was trying to troubleshoot this issue (spend a night without cell phone service.)

But i was able to get it working again.

1. Have another phone handy cause you will need it to contact you provider (t-mobile in my case)
2. Make sure that you have access to wifi cause you will need it to gain service back.
3. I removed the cellular plan from my account. so that my phone lost service completely. and no service was associated to my phone.
4. Called tmobile from the other phone and asked them re input the EID in their system on their end.
5. waited a few moments and went to add the cellular plan back to my account and then everything starting filling back in.
6. went to reactivate imessage and facetime and it worked with no issue.

Seems like that fixed the problem.

I'm not sure if the people having this problem are using esim or not but this seems to have done the trick and i am able to get and receive imessage and facetime calls again.

eSim here with T-Mobile also. Wonder if anything is common here. I did more or less the same thing to get mine working, but time will tell if it "sticks":

Do NOT do this at a time where you cannot speak with your cellular carrier on the phone, either because their support is closed or because you do not have an alternate phone nearby. You will also need your iPhone to be on wifi so it can reactivate

1. Settings > Cellular > Remove Cellular Plan. This will warn multiple times, so make sure you are ready to proceed with the rest of the steps. This will delete settings in your carrier's system.
2. Settings > About. Take note of the "EID" number, you should be able to tap-hold, then Copy it and paste into an email since in my case it was much easier to see on the computer screen.
3. Call carrier and tell them you need to update/add the EID on your phone number. Your carrier will probably make you go through some verification hoops (remember that they CANNOT send you a text at this time since your phone is not on their system; T-Mobile was able to email me a code instead). Give them the EID from step 2.
4. In my case, T-Mobile had me restart my phone, then I was prompted to install the cellular plan. After that iMessage (and Facetime) on the iPhone was able to reactivate on my cell number, and I am getting calls/texts on the iPad as well.
5. Cross fingers.

My solution is the one that has worked and I haven’t had any issues since.

I removed the cellular plan from T-Mobile from the phone and I then contacted T-Mobile and had them reassign my Eid to my plan and that solved the problems. Restarted the phone waited for the I haven’t had any issues ever since.

here are the steps that I posted a few weeks ago.

I was trying to troubleshoot this issue (spend a night without cell phone service.)

But i was able to get it working again.

1. Have another phone handy cause you will need it to contact you provider (t-mobile in my case)
2. Make sure that you have access to wifi cause you will need it to gain service back.
3. I removed the cellular plan from my account. so that my phone lost service completely. and no service was associated to my phone.
4. Called tmobile from the other phone and asked them re input the EID in their system on their end.
5. waited a few moments and went to add the cellular plan back to my account and then everything starting filling back in.
6. went to reactivate imessage and facetime and it worked with no issue.

Seems like that fixed the problem.

I'm not sure if the people having this problem are using esim or not but this seems to have done the trick and i am able to get and receive imessage and facetime calls again.

I have had this issue on and off since March 20th I think around the time of 15.4. I have tried all of the things mentioned beyond resetting my e-sim. I got on with a T-Mobile 2nd level support person and they mailed me a physical sim which just showed up April 13th. But since me ordering that and it showing ~April 11th/12th it seems to be that the problem no longer happens. I want to think that they solved some underlying issue but it would be good to get confirmation on this. One thing I noticed on my AppleID the phone number would keep dropping and I would have to add it back. Then when iMessage would work it would show 2 phone numbers one with iMessage/FaceTime and then one without but both numbers were the same. In the past few days it’s only showing one number under my AppleID settings and it shows iMessage and FaceTime there. So there clearly has been some change just hope we can get some confirmation so we can stop being in limbo. Attaching a screenshot but hid the phone number but know that they are the same.

I have the same issue. As soon as the IOS 15.4 finished, IMessage stopped working with my phone number. Tried everything.

reseting the phone and restore from the backup, tried turning iMessage and FaceTime off and back on, airplane mode, restarting the phone multiple times.

it either gets stuck on waiting for activation or shows the error that is was not successful.

I’m having the same issue I’ve spoken to apple and they are telling me to wait 24 hours. I’ve tried Everything stated above. Hopefully it gets resolved soon. Was working fine until the IOS 15.4 update.

I’m still trying to sort it, they are saying it’s my phone carrier issue but I’ve spoken to them 3 times and it’s not.. it’s being sent to a tech team at apple apparently as soon as I get any help I’ll pop it on here

I got a call from apple today and they said it’s been sent to the tech team.. one other thing they got me to do was send ‘HELP’ to 48369 but that text failed I’m in the UK so I’m not sure it would be the same number to text?

I’m having this issue. And I’m debating if I want to downgrade back to 15.3.1. Because this issue is just insane. I can’t text people. And it randomly kicks me off the iMessage network and I think I’ve text people even if it’s green bubble and it’s not going thru at all. This is a horrible situation to have.

This IOS software bug doesn't seem to be related to the brief system outage.

This IOS software bug has been going on ever since I updated my phone about a week ago. This brief outage was resolved. But the bugs and being unable to activate iMessage again persists.

Hopefully that will help someone, for myself personally I have a nano sim and I’m with Sky mobile unfortunately everyone I talk to is just as confused as I am with this whole thing.. hopefully it stays working for you!

Thank you for your suggestions!

I also have esim, I was on the phone with T mobile for 2 hours they updated EID, then it took about 12 hours to verify the phone, it worked for couple hours and then went off again. So annoying