Q: iMessage not working since 10.10.3 update

Your iMessage was never broken -- you just didn't hadn't signed in.

My problem is the same: iMessage is BROKEN! ...still waiting for Apple to fix their server. It's been a MONTH now since their last updates broke it for me and many other Apple customers. There must not be enough of us out here, though, since they haven't fixed it, even though Tier 2 Support knows all about it and receive many calls every day regarding this problem.

Sheesh...

AMEN - mine is doing the same thing! every setting is exactly how it was it simply is not working. blank messages and not syncing between devices, out of order (and missing) conversations!!!!! I am so sick of these rushed updates that create more problems than they solve (at least that is how it is beginning to feel).... i bought **** macbook and have been very happy with the syncing between my phone and iPad with messages etc. until these past few updates - now everything seems to be messed up. iMessage is also freezing or not opening on my brand new iPhone with that recent update.... sincerely disappointed. COME ON APPLE!!!

I have MANY problems since the 10.10.3 update- Safari will not connect to internet, iMessage is not synching across devices, and iMessage will not work at all on my MacBook Pro. Keeps saying I am "Disconnected". Also unable to read any links sent through Mail server since it opens in Safari(which is no longer connecting).

HELP APPLE, very frustrating!

So we finally found out last night that there is an issue with my Apple ID that needs to be fixed. Supposedly their engineers go into my Apple ID settings on their server to either "reset permissions" or try to figure out what's going on. How long does this take? A WEEK!! ...argh...and then I have to rely on my custom support guy (Jason, who's been fantastic, btw), to get back to me at the prescribed time (one week from now at 5pm). Ugh.

How do we know that my Apple ID is messed up? We created a brand new one and iMessage works with that. So it's not a setting on my computers/devices. This was after doing the following: 1) created a new User ID on my computer (no luck); 2) went into Keychain multiple times to trash certain files; 3) totally deleted my Keychain folder (it just repopulates upon restart...no problems).

At least I didn't do a factory reset, which would have done nothing to help this problem with my main Apple ID.

***, Apple??!!

Apple finally fixed my issue. How? Their engineers had to "reset" my Apple ID, which wasn't working properly. Whatever that means.

I'm glad they fixed it...but it took almost TWO months for them to get their act together to fix it. How did we know it was a problem with my Apple ID? By setting up another Apple ID and seeing if iMessage worked with that id (it did). Hence, the issue was with my original id. Sooooo...if you have an issue, immediately ask them to send a note to their internal engineers to "reset" your Apple ID (something about resetting the "permissions" -- or something like that). It takes them a week to get an engineer to look at it and reset the id. Ugh.

They should have done this from Day One!

Three days ago, I noticed that iMessage on my MacBook Pro was no longer synching with my other devices (iPhone and iPad mini). After finding this thread, I followed your step by step instructions and sure enough, my Apple ID password was missing. Entered my password and that fixed it! All of the missing messages started to update and were 100% synched in under two minutes. No issues since. Thank You KirKCameron and andriles!

Also, same setup and problems I experienced are highlighted below.

mpjohnson68 Apr 15, 2015 5:28 AM

- Beginning two days 04/14 (after I updated to OS X 10.10.3 and iOS 8.3, iMessage stopped syncing with other OS X and iOS devices on the same iCloud account. All on the same network.   

- Continuity and Handoff also do not work on the MBP...(worked great a couple days ago)

- MBP is on WiFi.

- I have cycled power, turned on and off wifi, logged out of iCloud, logged out of iMessage (on all devices). **I only logged out of iMessage on my MBP and iPhone**

- I did get notice on the other devices when I turned iCloud back on and wanted my keychain restored.

- MPB is also updated to 10.10.3 and no issues. All features work.

- iPhone and iPad are at iOS 8.3 (12F70, 12F69)

Also,  when attempting to send to known iMessage account holders I was not  getting the blue, rather the red highlight on the names and the "not  registered with iMessage" notice. **This is the first issue I noticed**

I am constantly being asked to login to iCloud

This works great, as long as you don't have Apple two-step verification.  In that case, follow the above and log out.

When you log back in, you will get a prompt to create an 'App-Specific Password'

1. Click 'Create'
2. You will get sent over to appleid.apple.com to log-in (you'll likely have 2 step verification here too)
3. You may or may not be taken automatically to Generate an App-specific password
   1. If you don't, go to Password & Security -> Generate an App-specific password
   2. Click to create an App-specific password and call it "iMessage & FaceTime"
4. You will have a generated code for the app (copy it)
5. Go back into Settings on the iPhone and as you log in, use this NEW GENERATED CODE as your password. 

This will save you hours, as tech support was originally unaware of this, and we had escalated this up to engineering. But on a whim Sarah from Apple got this info from a coworker who thot this might be a solution.  And it was!!!  Thanks to Apple support for the help!!