Q: When I try to start a conversation on my Macbook Imessages it says the contact is not registered with imessage? it happened so randomly, they are without a doubt registered but I can't send or receive any messages.
After my phone was stolen from me I continued to imessage through my laptop. I accidently deleted my message thread with my best friend so when I tried to send another message and open back up the thread it told me that her phone number and Apple ID was not registered with Imessage ?
I tried logging out of my Apple ID and back in but that didn't work and I turned on and off my laptop but that didn't work either. Can someone please tell me how to fix this ????
MacBook Air, iOS 9.3.1
Posted on Apr 25, 2016 3:54 AM
Hi,
Did you use this page to Disable the iPhone from iMessages ?
https://selfsolve.apple.com/deregister-imessage
Your Mac may not be fully logged in and the "not registered" alert tends to be a standard messages of the app not being able to get feedback details rather than the "truth".
IS it all Contacts that now get this Alert ?
IF not do some get "Not Delivered" alerts when Sending iMessages ?
This happens to be a Text Forwarded one but the Principle applies.
Try a NVRAM reset How to Reset NVRAM on your Mac - Apple Support
Try a Safe Boot
If those two things don't work check the Apple icon Menu > About this Mac
In this panel you have to click the line about the OS X version twice to show the Serial Number (the first displays the Build Number).
If this is there then try an Different Mac User account (Enable Guest of Create one in System Preferences > Users and Groups).
If all of these fail then the Apple ID in relation to your Mac's use of it in iMessages has been blocked by the iMessages server.
Try a different Apple ID that is also linked to iCloud in the iMessages account.
Go to Messages > Preferences > Accounts > iMessages
Sign Out of your regular ID
Sign In with the "new" ID.
If that does not work the issue is most likely a missing Serial Number.
If it does work it will be your Apple ID at the server.
As th Serial Number is used as well as the Apple ID and password to create an Auth Token the Server can block an ID based on it's use from a specific Device.
Hence it is still likely to work on an iPad or iPhone.
You need to contact Apple Support (same as Apple Care).
Explain you have and Apple ID issue (free to fix) as the Level one people are Script led to solve Software and Hardware issues at an Apple Care level.
It is likely you will need to speak to someone higher (ask to do so).
They may still want you to jump though hoops and data grab info as in some cases they don't know why this gets triggered.
Ask for the server to be reset.
They may want you to Upgrade if not using the latest version of the OS. (moving to El Capitan from Mavericks for instance)
They may ask you to Update to the latest (OS X 10.11.3 to OS X 10.11.4)
They may ask you to reinstall.
None of these are required and should not be done as they will not solve anything.
Insist (politely) that the server is reset.
They may involve the Engineers and tell you it will take 24 hours.
9:49 pm Monday; April 25, 2016
G4/1GhzDual MDD (Leopard 10.5.8)
MacBookPro 2Gb (Snow Leopard 10.6.8)
Mac OS X (10.6.8),
iPhone and an iPad (2)
Posted on Apr 25, 2016 1:49 PM

