Messages not working on Mac since upgrading to Sequoia 15.4

I have had this issue for a while where I couldn't send and SMS via my macbook, only iMessages. After digging around a bit I learned it was actually an issue on my phone.

To fix:

Open Settings on your iPhone > Scroll down and open Apps > Scroll down and open Messages > Scroll down and open Text Message Forwarding > Enable the toggle on your device

You might have to go and "Sync Now" in your messages preferences on your other device, but after that it worked as it should.

Hope this helps because it was a constant issue for me that I couldn't figure out for way too long.

Hi Just called Apple and a great tech person--had me go to settings, iCloud, messages, and hit sync. This reset things and all is working perfectly now.

Hi Just called Apple and a great tech person--had me go to settings, iCloud, messages, and hit sync. This reset things and all is working perfectly now.

I made my secondary profile an “admin” as well by giving admin authorities. It’s annoying to switch between the two when I need a file from that account, but it still makes work flow overall much easier with iMessage working on the secondary profile

I believe the problem started with Sonoma. It has now continued into Sequoia. And even though so many people are complaining about the problem, Apple doesn't seem to care at all.

I switched directly from a 2011 iMac running High Sierra to a Mac Studio running Sonoma. I've been working with Macs long enough to know how to help myself when problems arise, but some problems are caused by Apple and there's not much you can do about them.

So with the Mac Studio and Sonoma, this problem started where messages repeatedly fail to appear on the Mac. It happens almost every day.

I exchange messages with a friend almost every day. He writes them all from an iPhone – always the same one. So why most of his messages arrive on the Mac, but some repeatedly fail to do so, is beyond me.

All of his messages appear reliably on my iPhone. Every time!

I now also use a MacBook Pro M1, which also runs on Sequoia. Some of the messages don't arrive there either. I see the messages on my iPhone, but I usually reply to them on one of the Macs. Replying is no problem, but the message from him that I'm replying to simply remains missing.

And here's the thing: 

on my old MacBook Pro from 2011, which still runs High Sierra, ALL messages appear reliably.

And that leads me to conclude that there is a problem with macOS since Sonoma that the folks in Cupertino should finally address! It's just extremely annoying when you spend thousands of dollars or euros on Apple hardware and then get ignored by Apple when problems arise.

That is fine. To me it just does not make sense to come on a Support Site and think it is too much trouble to call Apple directly because people on YouTube and other forums are having trouble too. As you can see there has not been 1 fix that has helped users here, so your case indeed may be unique. Apple can perform remote diagnostics and also pull log files to see what is going on and it costs you nothing. You are not seeing people on Social Media telling you that everything is working great, the only posts are for those where there is a problem. That may led you to believe it is much more pervasive than it actually is.

Having the issue on my new MacBook Air M4, just purchased this week as well as my iMac and macMini. My iPhone works fine. Funny how it shows message fails to send but when checking on my phone it has gone. Recipients in the group all receive the message despite saying not delivered error. They are all using Android phones. This never happens when sending to an iPhone.

UPDATE:

A couple of days after updating my computer to Sequoia 15.4.1, iMessages on my laptop suddenly resumed working. The day I updated it (and the day it stopped working), I tried many of the "fixes" mentioned here -- syncing messages, signing out and back in, etc. The issue would appear resolved for a few minutes and then go back to green bubbles/SMS messages and say "not delivered."

I didn't explicitly do anything more to resolve this issue, but I am now able to receive and send iMessages without any difficulty on my laptop.

I also am able to send and receive SMS messages, but I used to be able to do that. That worked even with iMessage did not. My husband is unable to send/receive SMS messages on his laptop, but I think it's due to the fact that he doesn't have his Messages syncing across iCloud because he's too cheap to increase his storage limit - LOL!

I wish I had more help to offer those of you who are still unable to use iMessage on your computer.

After dealing with this for countless months now here is what I found, not a fix but causes. We live in a rural area with terrible cell service. Internet service is great 750mps. I have WIFI calling on. The following happens on a laptop, desktop, iPAD or iPhone, all Apple equipment. When I send a message to an Android device it will not go through unless I have 2 bars on cell service. Yes even using a desktop, my iPhone has to have 2 bars. Does not mater that I have full bars on WIFI. I can not make phone calls unless I have 2 cell bars to an Android phone or even Apple phones. Yes again, full WIFI bars. NOW using Face Time Video, iPhone to iPhone works perfectly, cell bars or no cell bars, or even SOS displaying it works. I believe the issue is somehow connect with WIFI calling.Not the ISP, this does it with 2 different providers.

After countless visits to websites and forums (including this one), I still haven't found a solution. Here's an example from my everyday life: Two days ago, I received four messages (three from one person, one from another), all of which arrived on my iPhone. Due to time constraints, I didn't read them, but only registered them on the lock screen. I wanted to deal with them when I got home. Once I got home, I did the following test:

I started up both M1 Macs (Studio and MacBook Pro).

None of the four messages arrived on the Mac Studio. They haven't yet. Three messages from one person arrived on the MacBook Pro. But the message from the other person is still missing.

And it keeps going. Even when the Mac Studio is turned on, a few messages keep failing to arrive. It can't be the sender's fault, because a friend who lives far away, in particular, texts me daily from home. So, why messages from him sometimes arrive and others don't, is a mystery.

And why all messages arrive reliably on my old 2011 MacBook with High Sierra is also a mystery.

For me, it's clear that the fault lies with Apple, and they failed at least in this regard with their Sonoma-era systems. And they won't care. They're more likely to care about visual gimmicks like their glass design.

It's been an issue (especially with non-iPhone messaging Android RCS) for about a year already! No better on 15.6.1. Happens mostly on OS X, as opposed to iPhone. Get it together, Apple!

I'm having the same problem and also tried rebooting my mac, signing out and back in to my icloud account, checking to make sure it's the correct and corresponding account. I made sure my settings were all good to go on my phone and on my mac.

The most I've been able to have happen is that it seems to send/receive extremely delayed texts (1-2 days after I've received them on my phone).

I am having the same problem immediately following the upgrade. It is only allowing me to send SMS to my contacts from my computer and frequently they do not go through (failed delivery). I've checked every setting as discussed here. No issues from the iphone, but synching and sending is intermittent and limited to SMS from my computer.

Same issue here, it is really frustrating. I recently updated my MacBook to MacOS Sequoia 15.4.1, and ever since my messages are either sending as SMS instead of iMessage, or just flat out failing to send. Messages are also not syncing completely. I've logged in and out of iMessage, restarted my MacBook, signed in and out of iCloud, and so on. Text message forwarding is enabled and correctly set up on my iPhone.

It’s been roughly 2 weeks for me now. Spoke with 3 different Apple reps on the phone, no fix yet. The last thing we did was screen record the issue and sent it to their engineers. I am waiting for resolution