High Sierra iMessage: An Error Showed up during Activation

Almost every Mac owner would like to switch to macOS High Sierra as it is the latest version of operating system released by Apple. However, pitfalls exist everywhere.

One of the most common issues is the presence of a bug during the installation and activation process. That High Sierra iMessage bothers plenty of MacBook Air users. No matter which High Sierra release it is, you risk facing this problem.

The situation looks this way: each time a user attempts to sign into iMessage, the application sends an error notification in several seconds after pushing the Sign In button. You will see the text appearing exactly this way: “An error occurred during activation. Try Again.”

Apple’s official support pages recommend a variety of actions, but what if they do not work? Those are updating iPhone to iOS11 and upgrading a MacBook Air, MacBook Pro, MacBook, or iMac to High Sierra. In other words, upgrading the available Apple devices to the recently released operating systems won’t work. They just do not accept Apple ID for login to FaceTime and iMessage. On the iPhone iMessage, for instance, it may work with the phone number, giving an activation error with Apple ID.

Where to Start from?

Before fixing the error, make sure there is an error. It might be necessary to take certain risks and share your personal Apple ID details with someone you can trust. Why? Let a third party try to log in with the help of your and then their Apple ID on your Mac. in case their attempts are successful when it comes to their IDs (meaning they can log in and apply Messages/FaceTime), the core problem is the user’s Apple ID.

That is when the best thing is to contact Apple support directly. You may discover that an Apple ID is a real problem. Be patient: the recovery process may take up to 4-5 days. Warning: if you give Apple a call after knowing the cause, specify that the problem is an Apple ID not to waste time. It will also prevent from getting charged.

Look at the possible solutions below – they work for both iMessage and FaceTime.

Check the Internet Connection

Is your Apple computer connected to the Internet? Are there any problems with the network? It is easy to find out: try loading websites or opening email attachments, for instance.

What about a Service Outage?

Scan the Apple System Status page for a temp outage influencing iMessage/FaceTime.

Pay Attention to Date/Time Settings

Select Apple menu. Go to the System Preferences. Pick Date and Time there. Check whether all three factors (time, zone, and date) are set properly.

Is the “Set date and time automatically” option chosen by default? Remove the checkmark from the box and pick it once more. There are cases when the option is greyed out meaning a user can’t press it. Just pick the lock sign and type the admin’s login details.

Are You Sure You Have the Most Recent Software?

Software should be up-to-date to function properly and quickly. Try looking for the latest updates to ensure the stable work of your Apple device as well as compatibility and safety.

Check the Apple ID

This advice is a bit different than the one with your friends checking whether Apple ID or Mac itself is the problem. Perhaps, the ID or password (or both) are incorrect. The best way to find out is to open your account page and log in with the ID you apply to enter Messages and FaceTime. In case it works. Launch the application and do the following:

  1. Messages: Pick Messages à Preferences à Choose iMessage account and pick Sign Out. Log in back with the ID applied to the personal account page.
  2. FaceTime: Select FaceTime and move to its Preferences. Find the Settings tab. Pick Sign Out. After that, log in once more using ID applied to the Apple ID account page.

Look for Third-Party Tools

Have you set up something like a firewall, VPN, or another networking tools? If yes, check if those extensions or apps are not preventing any of the network ports applied by the target software. It might help if you deactivate some extensions or apps and try iMessage once more.


Turn off the computer. Next, switch it on and push the Option, Command, P, and R keys altogether. Let them go in about 20 seconds. Mac will probably reboot.

After the startup process is over, launch System Preferences and modify the settings that were reset (e.g., display resolution or time zone).