Have you restarted the server? Or at least the main Services running on the server?
If so, and as long as its not crashing AC, I would ignore it. When we begin receiving those alert messages they usually go away after about a week's time.
Even if you get a hold of GA (gone away) Support they will only restart your services as I mentioned above and say you should be set. You may/may not get the message the next morning.
