VMware ESX: This product has expired

If you find you can’t Power On a virtual machine on ESX 3.5, and you’re seeing this in your error logs:

Message from esxserver.yourdomain.com: This product has expired. Be sure that your host machine’s date and time are set correctly. There is a more recent version available at the VMware Web site: “http://www.vmware.com/info?id=4”.

Then you can find the solution at this blog.

Thanks Todd, you just saved me from pulling an all-nighter. I thought I was going crazy!

Update: The first signs of this problem occuring are that, when you try to Power On a virtual machine, you get the error message: “A General System error occurred: Internal error”. After checking the Events log, you’ll see the more verbose error message earlier on in the post.