why did iMessage on my mac stopped working?It says it is inactive, and all contacts off line, yet im signed in to imessage/iclowd.

From the Messages Menubar/Messages/Accounts, check to see if iMessage is selected.

You're welcome and thank you.

I am now having the same problem, I go to log in as above and get this message -

The server encountered an error processing registration. Please try again later.

I even changed my password and it still doesn't work

I'm in the same boat as Iloveclarabelle. My last successful message from iMessage was 5th November. Since then iMessage seems to have dropped its sign in - probably following an update of some kind but as I don't use it every day I really couldn't be sure.

When I re-enter my Apple ID password at Preferences > Accounts I'm getting this failure:

Could not sign in to iMessage.

The server encountered an error processing registration. Please try again later.

Found more help on this post and:

1. Checked service status: iMessage and everything else green right now.
2. Signing out of iMessage was tricky when I couldn't sign in, but I did disable it on my phone in settings > messages > iMessage
3. I didn't touch my router as it has not changed since iMessage started giving me this trouble.
4. Checked my OSX version (10.8.5) and serial number
5. Verified Apple ID, hosts file as instructed.
6. Checked system prefs > network > advanced > proxy and ensured the SOCKS proxy was unchecked. This is a simple home setup, with no proxies.
7. Set flash player preferences to block all sites from storing info on my computer.
8. Opened keychain and removed all iMessage entries (ensuring I knew my Apple ID & password, which I'd just been using up there in step 5 anyway).
9. Enabled the guest account, and tried iMessage there. The account would not enable there either: Could not sign in to iMessage. The registering device does not have appropriate credentials.

Interestingly after step 9 there, my iMessage error has changed. I now get the same 'registering device does not have appropriate credentials' error instead of the original 'The server encountered an error processing registration. Please try again later.'

At this point apparently it's safe mode check, then NVRAM reset time.

I'm not going to reinstall my OS for iMessage !

But I would love to know if there's any other reason I might be having trouble.

Sorry, I didn't see any checkbox to select "imessage", could you explain a little more clear?

For some reason the path in my reply 3 months seems to be no longer available.

Go to Messages/Preferences/Accounts

In the Accounts Sidebar, select your iMessage Account and make sure "Enable this account" is checked.

I am having the same problem: I get the error message "registering device does not have appropriate creditials". This happened after I upgraded-any other solution than re-install?

Thanks!

it has been enabled. though doesn't work. says I'message inactive.

My daughter's says that too. It does not recognize the Apple Id password, even though I can log in to Apple Id every where else (ipod, desktop computer, itunes).

My iMessage is active after doing the following changes. Oh i was really ****** and at last found my own way. Thank God!

1. Open messages (which is inactive).

2. From the top menu go to messages -> preferences

3. Click on the accounts tab

4. Now click on the Details button.

5. This will ask you for your icloud username and password. Enter it.

6. Here most likely your Location would be set to empty or none. Select United States from the drop down or your country. My country was not in the drop down so I just selected United States and clicked Save.

7. Sign out from messages app.

8. Quit the messages app.

9. Reopen messages.

10. Sign in. That's it you are done.

Congrats!!! have a nice chat buddies.. ;-)

Thank you dear

after three days and lot of time searching the net for solution

you solved it for me.