Error Occurred during activation- MacBook Air
I never logged out of my iMessage or FaceTime accounts except one day I just switched on my MacBook (it was on Sleep Mode and wasn't turned off), and I found that I have been logged out of both FaceTime and iMessage. Now every single time I try to log in, it gives me an "error occurred during activation. Please try again" message.
I have tried restarting the system, turning it off for couple of hours and switching it on, but I am still stuck.
macOS High Sierra (10.13.2)