SLM: Certain clients sometimes/consistently cannot connect to the License Server, especially from remote locations

ID:    S137310
Published:    03 August 2009
Updated:    13 October 2021

Operating System(s)

  • All Unix
  • All Windows


  • Builder
  • Dimensions CM
  • Dimensions RM
  • PVCS Tracker
  • PVCS Version Manager
  • SBM
  • TeamTrack


In Serena License Manager (SLM) release 2.1.4, the FLEXlm core of SLM was upgraded from release 9.2 to 10.8. As a result, client libraries used in SLM 2.1.4-based product only wait 100ms for a response from the License Server if those clients only specify the name of the SLM server (and not port number as wel). This is quite a bit shorter than the timeout found in previous releases. 


If only a server name is specified, clients try to connect to that server by scanning for an SLM instance in the port range 27000-27009, waiting up to 100ms for a response on each port. If no response is received within that time, the next port is probed. Should a delayed response from a previously probed port come in after the timeout has expired, that response will get ignored as the SLM client has moved on to try the next port(s).
Customers with a centralized License Server may find that, with clients based on SLM 2.1.4 or newer, remote users either cannot connect to the license server, or can only intermittently connect to it, depending on the round-trip delay between the client and the SLM server. Some examples of error messages that may be shown:
Cannot connect to license server system. (-15,570): LicenseFeatureName (UserName)
11:54:55 Aug.03.09 [Error]
Access has been denied due to a licensing problem.  Unable to reach License Server @ServerName (as defined in ISLV file C:\WINNT\islv.ini).  Please contact your Serena administrator for further assistance.
Couldn't connect to the specified license server. Verify that this information is correct.
Customers who have both SLM 2.1.4-based clients (or newer) as well as older clients installed may find that the older clients still work, but newer ones do not.
SLM 2.1.4 based clients were first shipped as part of:
  • Serena Dimensions CM 10.1.0 and 10.1.1
  • Serena Dimensions RM 10.1.0 and 10.1.1
  • Serena ChangeMan Professional 9.4. This includes:
    • ChangeMan Version Manager 8.1.4
    • TeamTrack 6.6.1
    • ChangeMan Builder 6.4.1

Subsequent releases of products that use SLM (Serena License Manager) will have the same behavior, including Business Mashups and SBM.
Customers who manually replaced their mlclient libraries based on KB article P2416 are equally affected.



The best solution to avoid this problem is to disable the port scanning feature by using a fixed port, which increases the timeout wait from 100ms to about 20 seconds.
To do this:
  1. Change the SLM server configuration so that the main (lmgrd) server is always using the same port. You can pick the default value of 27000. For detailed instructions, please see KB article S136346.
  2. Specify the port number on the affected clients. Instead of just specifying "ServerName" or "@ServerName", specify "PortNum@ServerName" (eg.

    Unaffected clients may also specify the port but don't have to, providing the fixed port is still in the 27000-27009 range. If a different port number was used, all clients will have to specify that port number.

    To change the license server definition for:
    • Version Manager on Windows:

      Choose one of the following:

      • Use the ChangeLicenseServer.exe utility. This tool can also be accessed from Start -> Programs -> Serena -> PVCS Version Manager ### -> Change License Server.
      • Edit the ISLV.INI file in your %ISLVINI% directory (or in %windir%) and replace the SERVER= line in the [Licensing] section. (eg.
    • Version Manager on Linux/UNIX

      Choose one of the following:

      • The PVCS VM Administrator runs the following command to change that user's SLM server eference and the license.ini template file:

        vmreg -m "PortNum@ServerName"

        (eg. vmreg -m "")

        Existing Linux/UNIX users execute the following command to update their SLM server reference with the one from the license.ini template file:


        New users will automatically use the SLM server reference from the license.ini template file.
      • Indiviual Linux/UNIX users execute:

        vmreg "PortNum@ServerName"

        (eg. vmreg "")

        Can be used if the PVCS VM Administrator is not available, or when a single Linux/UNIX user needs to use a different license server.
      • Indiviual Linux/UNIX users edit the .islvrc file in their $HOME directory and replace the SERVER= line in the [Licensing] section. (eg.
    • TeamTrack / SBM:

      Choose one of the following:

      • Use TeamTrack Administrator / SBM Administrator (Options -> License Options).
      • Use SBM Configurator (License Server section).
    • Dimensions CM:

      Update the DM_LICENSE line in the dm.cfg file.
    • Dimensions RM:

      RM Manage > Workspace > Options > License > License Server


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