Repeated login prompts for Apple Messages on Mac

Problem solved for me. Went to support. They sent me this link

https://apple.co/IMFT-mac

I had to use a different browser than safari because it would open support app. Once I got the website opened it had me put in my phone number and it said “Request Submitted “. I had to wait 12 hours and I received an email from Apple stating “Your iMessage account is ready to use.” Followed instructions and it worked. All devices are currently working. Annoying but it worked.

After repeated efforts at zapping PRAM, restarting, etc., I finally had to get with Apple support to get Messages on my device (2017 MBP) unblocked. It turns out that the blocking is done by the serial number of the device. I wasn't spamming anyone, so I'm not sure how this could happen.

<speculation>If things go by serial number, then perhaps it's possible to spoof a serial number for a device. After all, how else could Hackintoshes run, as they have no Apple serial number? Perhaps my serial number got spoofed by someone sending out those wonderful spams insisting that you call a phone number to give away your life savings.</speculation>

Same issue on 2 macbooks and 1 mini. This issue (so far) is NOT happening on my phone or ipads.

In my case, I have 1-3 seconds before being prompted to sign in again.

I was able to quickly open settings during one of these attempts and I don't believe we ever actually get signed in (the information in settings is blank, instead of showing, for example, my name, etc).

Same problem here. 2 Mac minis and 2 iMacs. When I go to Settings-Apps-Messages on my iPhone, none of the other devices show on "Send & Receive". Under that there is a "Use your Apple Account for iMessage". Asks me to sign in and I get a "iMessage Activation" error. Nothing after that :(

Same problem here on 2017 MBP using macOS Ventura (13.7.8 (22H730)). First noticed yesterday (Sep 12, 2025). Makes two-factor authentication less useful. Makes sending texts from a place where I can type rapidly impossible.

Same here. 5K 27" 2017 iMac. The app opens, asks me to log in, loads and runs for a few seconds, then reverts to the login prompt. It started a while ago, slightly different problem, but now this is constant.

This seems to be a widespread issue that has popped up in the last few days, affecting only Mac laptops and desktops.

Or an even more embarrassing bug involving many versions of macOS, since my Ventura 13.7.8 is having the same problem. Ugh.