How to Fix iMessage

Jan 5, 2020
Gigabyte Z390 Gaming M
RX 590
MacBook Pro

If your old motherboard is faulty and/or is never going to run MacOS again then you can use the same config.plist on the new motherboard including the critical system id's such as S/N, MLB, ROM, UUID ... etc without a problem.

However if the old motherboard is still going to run MacOS then you should generate all new critical system id's.


It is faulty, but I suppose there is a very small chance it could be refurbished and someone could use it to build a hackintosh. I'll replace my system ids. Thanks for the reply.
Dec 26, 2012
Dell Latitude e7470 (Clover)
HD 520
iMac, MacBook Air, MacBook Pro
Mobile Phone

I followed the steps to the best of my ability.
I contacted apple as I got the familiar error message:

You cannot sign in to iMessage on this Mac at this time.

To use iMessage with this Mac, contact Apple Support and provide the code below.

Customer Code: xxxx-xxxx-xxxx
Apple ID: (my email address)

After contacting them and providing them with the code, the first device began to work as expected. However, this second device continued to give the same error message, even after at least a thousand different representatives across a hundred ranks tried to activate it on their end over the past week. I attached my Clover folder, as I want to make sure that stuff like the serial number, MLB, ROM, etc. are appropriate for iMessage.

This is happening on MacOS 10.15.6 Catalina. An Apple ID that has been used for this device in the past is working.

Update #1: I found out that my current MLB (Board Serial Number) has not changed since the days where my system was defined as MacPro3,1. Obviously, this is not good, as my system is now defined is iMac14,2. So I generated a brand new MLB corresponding with the iMac14,2 serial number using and pasted it into Clover.

Now I have a different "Customer Code" or Verification Code, so I'm going to contact Apple again, telling them I did something along the lines of an SMC reset or firmware update.

On a side note, after I contacted Apple (before I posted today), my "invalid" Serial Number magically became valid in their system. Though there is no purchase date, warranty, etc., so I doubt my serial number is actually conflicting with a real Mac, let alone that it was invalid when I checked the first time.

Update #2: Even after changing the MLB and giving them the new code, it still didn't work. I think I "spoiled" the serial number. I just changed serial number, made new values for everything (ROM, MLB, SmUUID, etc.) and gave them the code for a third time. Works fine now.

Moral of the story? If you contact Apple and it still doesn't work after you give them the code, start COMPLETELY fresh (new SN, new MLB, new ROM, new SmUUID, etc.) before trying again (I also deleted iMessage files just in case).
Last edited:
Jul 31, 2020
Z370 Aorus Gaming 7
RTX 2080 Ti
Hello everyone,

Whenever I try to login to iMessage it appears to authenticate, and after a few seconds the login prompt appears again. I tried to login with another Apple account of mine and was able to login and text as expected, but I keep running through the issue above when I use my main account.

You might think that my account is locked, however, I'm able to use iMessage just fine on my iPhone and I even checked with Apple support on the account's status and they confirmed that it's not locked.

Appreciate all the help and support.