I am getting an error on upgrading from 8.0.3 to 8.0.4. How do I go about dealing with this.

Thanks

ZCS upgrade from 8.0.3 to 8.0.4 will be performed.
ERROR: Unable to reach the Zimbra License Activation Server.

License Activation is required when upgrading to ZCS 7 or later.

The ZCS Network upgrade will automatically attempt to activate the
current license as long as the activation server can be contacted.

You can obtain a manual activation key and re-run the upgrade
by specifying the -a activation.xml option.

A manual license activation key can be obtained by either visiting
the Zimbra support portal or contacting Zimbra support or sales.