Messages not working on Mac since upgrading to Sequoia 15.4

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.

The problem is getting worse of Message Failed to Send. Not only is it with the latest version of macOS BUT it has migrated now to my iPad Pro. Oddly enough the phone shows the messages do indeed go through. It has to be an iCloud issue, in my unprofessional amateur opinion.

I was having the same issue. The suggestion to sync Messages with iCloud is not practical for me as iCloud storage will be exceeded. To fix the issue after updating to Sequoia, I went to Messages, Settings, iMessage. Select Sign Out and then sign back in. For me, this worked.

Just fixed this issue with the help of support. They had me confirm that text message forwarding was turned on from my phone and then asked me to sign out of imessage on my computer and sign back in :) Hope this helps!

I had this issue too (in the shape of Messages being super busy with the rainbow wheel shortly after launch, to the point of being completely unusable).

Solved by deleting /Users/you/Library/Messages and restarting the Mac. Note that this might lead to loss of message history, but in my case the Mac was less than a week in use, so not an issue.

There is a problem with Messages Version 14.0 (1402.600.41.1.5) and Sequoia 15.5. The Synchronization in Message Settings/iMessage Synch Now command is not working.

T

he only way around this is to use the System Settings /Apple Account/iCloud/Messages Synch Now function.

If you have a Time Machine backup done in a earlier version of macOS - in this case, ideally in macOS 15.3.2 - you can always erase the Mac and reinstall it through the Time Machine backup

Same boat, I just updated today and it is SO frustrating!

do you know if there are any other considerations when making a secondary profile? do you still have all the necessary permissions?

It still comes and goes for me. Hopefully it stays working for you.

None of the suggested fixes have worked for me. Weirdly, SMS to Android uses syncs and works well from my Macbook, but no Apple-to-Apple iMessages are syncing or going through.

Funny Apple to Apple works for me but not SMS to Android, the exact opposite from what you are seeing.

I don't think anyone is listing to us. It also does it in the new bet? version. (cant say the word, comment gets deleted)

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.

Priyaluna - Are we talking about doing this on a Mac or iPhone? On my Mac I do not have a messages under iCloud.