iMessage on my mac says every contact is not registered with iMessage

Add one more person -

Since 9/9/2014, my iMessage on my iPhone works fine but my iMessage on my Macs and iPad stopped working, with all my contacts showing as "xxx is not registered with iMessage". My phone was running iOS7, has updated to 8.0, then 8.02. My iPad is running iOS7, my iMac Mavericks and my Macbook Pro Maverics. This happens across multiple ISPs, wifi and verizon.

FWIW, I have been in contact with Apple engineering, it appears to be an Apple ID issue, they have resolved this for me, (not sure what they did) and I am still waiting for an answer to what they found. I had 5 devices affected by this, 2 iPhones, iPad, iMac and a Macbook Pro. My AT&T iPhone was only phone working, all other devices look like I was having a conversation with myself and I could not reply. Except for the Verizon iPhone, I could start new messages, but only SMS.

I have several friends who I text often from my MBP (they're all iPhone users), and all of a sudden, their names/phone numbers turned to RED and I get the dreaded message that they're not registered! I've read through all responses on this thread and tried all suggested remedies, but found only one thing that worked...PRAM/NVRAM reset. THANKS RALPH for your suggestions and tips : - )

Thanks for the tips. I have read through this entire post with no prevail. I have tried everything except for calling Apple themselves. My iMessage stopped working on September 4th. My iPhone 5 runs it just fine, of course...

Quick question. When it suddenly started working, were you signed in via the Messages app? Also, was the app quit and then reopened when you discovered it started working, or was the app active and just magically started working? And was your computer asleep or off or restarted or anything? Sorry about all of the questions, but I would just like to know. Thanks a bunch!

I have a MBP and an iMac (and my iPhone). I am always signed in to all of them and before last month it worked flawlessly. Then it didn't.

Then it did, as above.

Then last night it stopped working. No error message this time. Just fails to send messages on my MBP and iMac. I get the little red ! badge next to each failed message.

Just gave things a try this evening and interestingly enough I can send messages to myself now. iMessage recognizes that my phone number is registered with iMessage and my message goes through. It appears it only works for sending messages to myself though. Progress though!

I had never thought to try to send an imessage to myself. I just did, using my MBP, and it worked, but the message did not show up on my phone. But it did show up on both the sending and receiving side of the window on my computer, so it technically sent. This just makes me even more confused. Some people here have posted that it spontaneously started working on their computers, but it never did on mine, so it wasn't a universal thing. Just hoping to get it figured out sometime.

This has worked for me the entire time. I can send iMessages to myself, but they do not appear on my phone. The ones I send to myself on my phone do not appear on my MBP. Oh well... I guess I'll just wait for the magical overnight fix!

Ralph, that is correct. The contact names stopped turning red the other day and for a short time, messenger worked fine on all devices. Then it stopped working again, with a different behavior, that of the exclamation mark badge next to undelivered messages. The names in the To line now look fine.

It's suddenly working for me again. I noticed a red "1" on the top right of the application, and before I could click it, it went away. Then I checked the app, and everything was back... Hope everything works for you guys as well!

I was skeptical of these "magical" overnight fixes, but this morning, 'voila!' the last day of messages from my phone were on my Mac and I was able to send a text to another iPhone from my Mac. Awesome. Hope it stays.

However, my iPad is still afflicted. No messages and when I tried to send one, I got the same little red "!", Almost there...... 😟

UPDATE: I decided to sign out of iMessage on my iPad and sign back in to see if that would help this time. Now I am getting the message that my user name or password are incorrect. Why????? :-/

iPhone and Mac still working.....

Someone may have already posted this, I didn't read all the comments.

I was having the same problem and couldn't find a solution until I remembered that I changed my apple id password recently. After I went into my setting on my iPhone and signed in under my new password it popped up on my mac asking if I wanted to add my number and of course I selected yes. This seems to have resolved the problem...until next time of course.

Amazingly this morning my iPad started receiving messages! So now all devices are working. The timing of this seems to coincidental to not be related to the Apple event tomorrow. Were they working out the final bugs with iMessage before the release of Yosemite? We may never know. At least its working. Hope its fixed for the rest of you was well!

Thanks for all the help along the way, especially you Ralph! ;-)

Mine just started working again about 5 minutes ago, without me doing anything to my computer. I have no idea what the problem was, but I am thankful it's working again. Good luck to anyone that is still having problems.