could not sign in to iMessage an error occurred during activation

[brainwave89]

After installing a fresh copy of Mojave on my mid-2010 Mac Pro I received the following message.

could not sign in to iMessage an error occurred during activation.

The machine is listed under devices when I log onto iCloud.com with my account.

Any suggestions on how to solve this error is appreciated.

 

[Nikolay Polyakov]

Any suggestions on how to solve this error is appreciated.

Try to reset NVRAM - it’s worked for me some time ago when I had the same issue.
Here’s the help article from the Apple: Reset NVRAM or PRAM on your Mac.

 

[brainwave89]

Thank you Nikolay but didn't help.

 

[BrianBaughn]

In the past there have been server-side issues with iMessage activation. A call to Apple might need to occur.

 

[Tammy Murphy]

I'm getting the same issue after installing the 2020-001 update on High Sierra (early2009 MacPro)
Tried resetting NvRam as well, no dice, and there are no other updates to do.... It's driving me crazy!

 

[grooby]

Has anyone able to find a solution for this? I am on an Mac Pro 4,1 that's updated to 5,1 and right now I can't sign into imessage nor facetime. Appstore download also stopped working too.

However, same AppleID has no issues on my iphone nor ipad pro.