You are having an issue loading a license key and are seeing a 'Host id error' and a 'java.net.UnknownHostException' in the IntroscopeEnterpriseManager.log
file located in the <ENTERPRISE_MANAGER_HOME>/config folder when installing an Enterprise Manager in a Linux/Unix environment.
You will still see this error even if the hostname and IP address in the license file matches the machine hostname and IP address.
You must configure the /etc/hosts file on your Linux or Unix system by adding the loopback IP address and hostname for the machine.
[root@<HOSTNAME@gt;/] #cat etc/hosts
#Do not remove the following line, or various programs
#that require network functionality will fail.
127.0.0.1 <HOSTNAME> localhost loopback
Note: An IP address can have multiple hostnames; in this example, the hostnames are: <HOSTNAME>, localhost, loopback
Once this configuration has been made, restart the Enterprise Manager. The license key error will be gone and the Enterprise Manager will start correctly.