NI License Manager Hangs When Querying a Volume License Server

Updated Jul 31, 2023

Reported In


  • NI License Manager
  • Volume License Manager
  • Volume License Manager 3.0

Issue Details

I am licensing my software using a Volume License Agreement (VLA), but after I specify the server name, the NI License Manager (NILM) hangs or freezes indefinitely, and I am forced to end the process in the Windows Task Manager. In addition, I cannot check out licenses or use the Volume License server to license my NI software.


NOTE: It is a recommended that you back up the registry prior to making any changes. This can be done by exporting the registry key prior to editing it using File»Export

Usually, this hang is caused by a communication problem with the license server over the secondary or vendor port. Before troubleshooting, you can stop the hang by disabling the license server request. The process depends on which version of Windows you're using:

For Windows Vista, 7, and Newer:
  1. Close NI License Manager.
  2. Navigate to C:\ProgramData\National Instruments\License Manager\Data
  3. Either rename or delete the servers.ini file.
  4. Open NI License Manager. It should no longer request a license from the license server.

For Windows XP and older operating systems:
  1. Click Start»Run, type regedit, then click OK to launch the registry editor
  2. Navigate to HKEY_LOCAL_MACHINE\SOFTWARE\FLEXlm License Manager
  3. Change the value of the NILM_LICENSE_FILE key to C:\\Program Files\\National Instruments\\Shared\\License Manager\\Licenses

After Disabling the License Server Request:
This has now disabled the license server option, allowing you to access NI License Manager. To troubleshoot the underlying cause, complete the following steps:
  1. Have the volume license administrator ensure that the SERVER line in the volume license file contains the fully qualified domain name of the server
  2. Ensure that you can successfully telnet to both VLM server ports.
    • Try pinging the server from your client computer, both using the IP Address and the computer name of your server
  3. If you have set up a FLEXnet server with LMTOOLS and are changing the default licensing port, be sure that the new port number is reflected in the license file and that the new port is not blocked on the server machine.
  4. If you use a System Environment Variable of LM_LICENSE_FILE to point your clients to the server, remove it and replace it with a vendor specific environment variable (i.e. [Vendor Name]_LICENSE_FILE). This environment variable will supersede NI's mechanisms to point the client to NI VLM. To access this value, right-click My Computer, then select Properties»Advanced»Environment Variables
    • ​​If you use an alias name for the server, try just entering the server name or IP address directly.
  5. This issue can also be caused by a missing DNS suffix, preventing proper communication. Complete the following steps to check whether you are missing DNS suffixes:
    1. Navigate to Start»Control Panel, then open Network Connections
    2. Right click Local Area Connection, then select Properties
    3. Select Internet Protocol (TCP/IP), then click Properties
    4. Click the Advanced button
    5. In the DNS tab, check that the domain on which the License Server is connected appears in the DNS suffixes list. If it does not appear, click Add... to add the suffix to the list 
    6. If necessary, manually add the local DNS lookup for the VLM server
  6. Check the contents of the lmgrd file on the server to verify that the server is reserving a license for your computer
  7. Try entering the server name as both <Computer Name>:<Port> and <IP Address>:<Port
  8. Temporarily disable your antivirus software and firewall to be sure they are not interfering with network communication

Additional Information

In Windows Vista, Windows 7, and newer operating systems, the license server information is stored in the ProgramData folder. Whereas, Windows XP and older operating systems, disabling the server request will require a change to the Windows Registry.

Here are some extra troubleshooting steps if the initial steps do not work:
  1. If this computer was configured automatically using a batch file, try entering server information manually
  2. If there is a computer nearby that connects properly, try switching computer locations to verify that cables, network entry point, or some other physical issue isn't introduced
  3. Perform a Wireshark trace to see if TCP/IP communication with the server occurs
  4. If your computer was configured using a Windows Image, verify that you do not have the same computer ID or name as another computer on the network
  5. Please check with the local software administrator if they use any external network software (network load balancer or other proxy configurators) as similar issues might be caused by them. If such software is being used, the hostname in the license file might have to be renamed to the virtual IP of the load balancer.
  6. Uninstall and reinstall all NI software .