Floating error: -15 Cannot connect to license server system.
This licensing error occurs when our design tools cannot establish a connection to the FlexNet license manager.
Possible problems include:
If your are accessing from a different computer, check that the client machine has access to the license server. Verify that the firewall ports used by FlexLM are open between these computers.
See this page: Ports used by FlexLM
Make sure The license manage port number is set to the correct port, by opening a browser where the FlexNet license manager is hosted and go to the Server Configuration Section;
Administration > Server configuration > License server configuration
Configure your product license utility using the correct port no.
Refer to Product license configuration for more details.
Check that your firewall is configured to allow the software to connect to the license manager.
Or disable firewall on your machines.
Disable firewall on CentOS 7 (RHEL 7)
For Linux and MacOS
If Lumerical tools and FlexLM are running on the same machine.
- Check that the host file is appended as:
$ sudo vi /etc/hosts 127.0.0.1 <machine_hostname> localhost localhost.localdomain localhost4 localhost4.localdomain4 ::1 localhost6 localhost6.localdomain6 <your_machine_IP> <machine_hostname>
- for example: computer name is
linx_serverand IP address is
/etc/hostswould look like:
127.0.0.1 linx_server localhost localhost.localdomain localhost4 localhost4.localdomain4 ::1 localhost6 localhost6.localdomain6 linx_server 192.168.1.100 linx_server
After changing the above file, restart FlexLM
/etc/hostsfile should also be updated whenever the HostName or IP address of the license server machine changes.