The most common cause for the license server failing to start is that there are no served licenses in the server. To start the license server, there needs to be at least one served license in the licenses directory.
When you install a new license server, there are no served licenses in the licenses directory and the license server does not start until you activate a license from SPDC and copy it into the licenses directory. Other causes include:
The license activated from SPDC was an unserved license. Examine the license files. Served licenses always start with a SERVER header. If you do not see a line starting with SERVER at the top of the license, you are using an unserved license which does not work with the license server.
If you are using a specific port number for the license, that port number may already be in use. Use netstat -a to verify that the port number is free. If not, free the port or use a different port number for the license server.
The host name recorded in the SERVER header does not match the actual host name. The host name is recorded next to the SERVER keyword. If it does not match, correct the host name in the license file or set it to this_host, which is a keyword that works with any host name.
The licenses copied may be activated for a different machine. Examine the Host ID next to the host name in the SERVER header. This value must match the Host ID for the machine where the license server is running.