Precedence for determining the Autodesk license server

The Autodesk network installation has several methods to determine the Autodesk License Manager. These are the

  • ADSKFLEX_LICENSE_FILE environment variable
  • ADSKFLEX_LICENSE_FILE registry key
  • LM_LICENSE_FILE variable
  • licpath.lic file and
  • License Finder dialog box configuration.

This document notes these methods, and clarifies their respective precedence:


1. ADSKFLEX_LICENSE_FILE environment variable

When running an Autodesk software product that uses the FLEXlm based version of the Autodesk License Manager (AdLM), it first reads the environment variable ADSKFLEX_LICENSE_FILE to determine where to look for its network license.



If the servers specified by ADSKFLEX_LICENSE_FILE are not available, or are out of concurrent licenses, the client reads a registry key to determine where to look next.

According to this article, the registry key is:


From our experience, the registry key is:



3. LM_LICENSE_FILE environment variable

Similar to the ADSKFLEX_LICENSE_FILE environment variable, the LM_LICENSE_FILE environment variable also points to a specific FlexLM license server. This variable It is common to all Flex enabled applications, so it is not recommended for use on a multi vendor environment.


4. licpath.lic file

The network installation creates a licpath.lic file. It is created on the client workstation for a client installation, and created in the run-tree folder on the server for a network heavy installation. The licpath.lic file must contain the following lines:

SERVER <Server name> <MAC address>


What is LICPATH.lic

The Autodesk LICPATH.lic file is created on client workstations during an Autodesk network installation. This file specifies the license server and lmgrd port number from which the client will try to obtain a license.


File format

According to Autodesk’s knowledge center, the format of that file should be:

SERVER server_name 000000000000



According to our experience, this format does not always work:

  • The actual MAC address needs to be specified,
  • The lmgrd port numbers is sometimes required, and
  • server_name could be either the name or IP of the license server.

So, a working format on our client machine is:


SERVER My_Autodesk_Server_IP My_Autodesk_Server_MAC My_lmgrd_Port_Number



For example:


SERVER server2012_autodesk 005056012345 27000


LICPATH.lic location

The LICPATH.lic file is located adjacent the Autodesk run file, one per licensed feature. I.e. there may be several such files located on the client machine in folders such as:

  • C:\Program Files\Autodesk\Autodesk AutoCAD Map 3D 2022
  • C:\Program Files\Autodesk\AutoCAD Map 3D 2013
  • C:\Program Files\Autodesk\AutoCAD Map 3D 2012


LICPATH.lic precedence

As listed on this document, there are a few parameters that take precedence over the LICPATH.lic file. These are the

  • ADSKFLEX_LICENSE_FILE environment variable
  • ADSKFLEX_LICENSE_FILE registry key, and
  • LM_LICENSE_FILE variable

In order to make sure the LICPATH.lic file takes effect, the parameters above need to be deleted or nullified.


5. License Finder dialog box

If upon application bring-up all the above methods have failed to determine the location of the Autodesk license manager, The “FLEXlm License Finder” dialog box appears and states that:

“Your application was not able to obtain a license because the FLEXnet license server manager could not determine where to find the licensing data it needs”

Autodesk requires the user to either “Specify the License Server System” or “Specify the License File”. Select “Specify the License Server System” and click Next. The UI will prompt you to type in the Autodesk license manager location.



1. The dialog box configuration changes the ADSKFLEX_LICENSE_FILE registry key, so it will take precedence over licpath.lic and LM_LICENSE_FILE. In order to return to those methods the ADSKFLEX_LICENSE_FILE key would have to be deleted from the registry.

2. OpenLM interfaces the Autodesk FlexLM based license manager to provide real-time application usage metering and license usage statistics. It automatically optimizes license utilization for the benefit of users and license administrators alike.

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