6.6 Why am I getting FlexNet error -15: Cannot connect to floating license server system?

If you are using ARM software products with a floating license, your workstation must be able to communicate with a server running FlexNet server software. If such communication cannot be established, a commonly reported FlexNet error code on the client is -15.

Possible reasons for FlexNet error code -15 are:
  • The wrong license file is being referenced by the application program.
  • The floating license server specified in the license file has not been started.
  • You are using the wrong port@host information.
  • The vendor daemon specified in the license file is not running.
  • The hostname in the license file is not recognized by the system.
  • The network between the client machine and the server machine is down.
To solve these issues, check that you have started your floating license server or servers. You must also check that your client have been correctly configured. The Tool Licensing FAQs on the ARM Technical Support website might also be helpful.
You can try running tests on your server or client computers to identify possible causes of the failure:
  1. Try running the lmutil lmdiag utility, which is designed primarily for this purpose.
  2. Verify that the application is referencing the correct license file.
  3. Verify that the vendor daemon, armlmd, is running. You can use ps on the server to look for the daemon on Unix/Linux, or the Windows Task Manager.
  4. Examine the server log file to see if any problems are reported, particularly messages indicating that the vendor daemon has quit.
  5. Run lmutil lmstat -a on the server machine to verify that the vendor daemon is alive.
  6. Run lmutil lmstat -a on the client machine to verify the connection from client to vendor daemon across the network.
If none of the above tests identifies the cause of the licensing failure, check whether your client machine can communicate to the server over TCP/IP using a utility such as ping. If this fails, then it is possible that communication is being blocked between the server and client.


Your floating license server and client might be on opposite sides of a firewall. If so, you must configure the firewall to allow access to fixed ports for both the lmgrd and armlmd license daemons. Define these ports in the server license file by modifying the top of the license file as shown, substituting your own values:
SERVER myserver server_hostid 8224
VENDOR armlmd port=portnumber


If your floating license server and client are on different subnets, then using the fully qualified domain name or IP address of the server might solve the problem. Using the IP address normally circumvents issues arising from domain name resolution.

Server hostname length

There is a character length limit for server hostnames used in the license files. For FLEXlm 8.1b and older, this limit is 32 characters. If you are using newer versions of FlexNet, the limit is 64 characters. If your floating license server name is too long, you must use the IP address of the server instead of the hostname in the license file and client license environment variable.

Intermittent failures

You might encounter intermittent licensing failures if your server is under very heavy load, for example, if you use automated build scripts. These failures can be caused by intermittent networking failures. The current versions of the ARM development tools are more resilient with respect to such temporary network interruptions. If you are using older tools, consider adding retry capability to your build scripts to work around the behavior.
Related reference
9.2 armlmdiag utility
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