SMS texts messages are received on iPhone fine but is only forwarded to one of the Macs, regardless of the model of Mac.
I have a slick Mac Air that I take with me everywhere and a sexy iMac at home. To keep all my offline data synced, I find it easier sometimes just to restore my Mac Air to the iMac or vice versa. The restoring process is not difficult, just use the Migration Assistant with the connection to a Apple Time Machine.
I soon find out that the SMS text messages that I receive on my iPhone would only be forwarded to one of the Macs, not both. I turned off iMessage on the iPhone then enabled it again but I can only see one of the Macs displayed under the Text Message Forwarding option. For example:
My research online led me to an Apple Support Forum. The poster Macsterguy explained this error as a Keychain issue which made total sense. Because the user on one Mac was restored from another, it would be possible that for the users on both Macs, the restored and original, to have the same user ID (UUID). In that case, the two Macs could be misinterpreted as one to the iPhone. Follow these steps to check the user UUID:
- Open System Preferences
- Click on Users & Groups
- Right click on the user in the current user list
- Select Advanced Options (if this does not appear, check that the “Click on the lock to prevent changes” option at the bottom of this window has been turned off.)
I would not advise you to change anything under the Advanced Options.
- Turn off the iMessages option under Messages on the iPhone (see the image above for the location of the option)
- Login to ALL Macs as the restored user
- Sign out of iMessage on ALL the Macs via the Messages application
- Open Messages application on the Mac
- Go to Menu
- Click on Messages, then Preferences
- Click on Accounts tab
- Select the account then click on the Sign Out button
- Quit the Message application on ALL the Macs
- Open the Keychain application on ALL the Macs
- Backup the key “com.apple.ids: localdevice-AuthToken” on ALL the Macs
- Delete the key “com.apple.ids: localdevice-AuthToken” on ALL the Macs
- Restart ALL the Macs and the iPhone
- Sign in to iMessage on ALL the Macs and the iPhone
Now you should see multiple devices listed in the iPhone.