This article is a legacy article. It applies to previous versions of the Liferay product. While the article is no longer maintained, the information may still be applicable.
During the course of normal usage, the following error was received: com.liferay.portal.NoSuchVirtualHostException: No VirtualHost exists with the key {hostname=}
Resolution
This issue is caused by the server being publicly reachable. The errors are caused by search engines trying to index the site, assuming that the server name is the virtual host of the site (which in our case doesn't exist).
To resolve, check through network settings to ensure that the server in question is only accessible from desired locations. A likely instance would be setting it so that only Apache or some other Web Server or load balancer could access it. This would resolve the issue as search engines would now be prevented from accessing the site.