Why do I receive License Manager Error -97?

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Why do I receive the following error?
ERROR: License Manager Error -97.
The desired vendor daemon is down.

Accepted Answer

MathWorks Support Team
MathWorks Support Team on 22 Feb 2023
Edited: MathWorks Support Team on 22 Feb 2023
This issue generally indicates that the MATLAB License Manager (MLM) process failed to start because the required ports are not available. The cause of this error may be due to one of the following:
  • Port Conflict
  • /var/tmp/ Conflict
  • Incorrect or Outdated MLM
  • Incorrect Host ID
  • Expired License

Port Conflict

When the port defined by the server license file is already in use, the License Manager will not be permitted to start.
To resolve this issue, you must set different ports for each license manager that you are running. Ports are defined in the first two lines of the license.dat file used by the license manager.
For example, in this license.dat file:
SERVER license-server-name 0123456789AB 27000
DAEMON MLM "C:\Program Files\MATLAB\R20XXx\etc\win64\mlm.exe"
  • lmgrd.exe is set use port 27000.
  • MLM.exe uses a random port by default, unless a port is manually defined.
If the license.dat file is edited as follows:
SERVER license-server-name 0123456789AB 27050
DAEMON MLM "C:\Program Files\MATLAB\R20XXx\etc\win64\mlm.exe" port=27051
  • lmgrd.exe will now use port 27050.
  • MLM.exe will now use port 27051.
After the license.dat file is updated, you must restart the network license manager:
Next, change the port number used by MATLAB on the network client.
Update the client's network.lic file. This file is one of the following:
  • (Windows) - $MATLAB\R20XXx\licenses\network.lic
  • (Linux) - /usr/local/MATLAB/R20XXx/licenses/network.lic
  • (MacOS) - /Applications/MATLAB_R20XXx.app/licenses/network.lic
Update the SERVER line in the client license files to match the SERVER line in the license file for the license manager.
There may also be a port conflict if the firewall is blocking the port. To verify that the firewall is the cause, temporarily disable it—if it is safe to do so.
If disabling the firewall allows licenses to be checked out, you will need to allow the MLM and LMGRD to pass through. It is possible to create program-based exceptions to the firewall in Windows and  MacOS allowing any port from the MLM vendor daemon. On Linux, you must use the port number.

/var/tmp Conflict

To resolve this issue, follow these steps:
  1. Remove the lockMLM file and the lm_TMW files from /var/tmp.
  2. After these files are removed, restart the license manager.
If you still receive the same error, an existing license manager or vendor daemon process might be the cause. The $MATLAB/etc/lmdown script shuts down a running lmgrd and MLM process. Sometimes the lmdown script can fail in its task.
If this occurs, the most effective way to shut down the license manager daemon is to use the UNIX "kill" command as follows:
1. Determine whether the license daemons are operating.
Depending on your system, use one of the following commands:
ps -ef | grep lm
ps agx | grep lm
2. Check the output to see if any LMGRD and "LM" or "MLM" associated with MATLAB are running. If so, kill all daemons manually by executing (root user may be required) the following command for each process.
kill <pid of daemon>
3. Restart the daemons by running $MATLAB/etc/lmstart.
If the error still remains at this point, it is also possible that the vendor daemon is trying to run on an occupied port. To resolve this, see the above solution for Port Conflict for changing the ports used by the SERVER and DAEMON lines.

Incorrect or Outdated MLM

To resolve this issue, make sure you’re running the latest version of FlexLM. Version 11.18.1 is the minimum required to serve licenses for R2022a and newer.
Follow these steps to check the version of FlexLM on Windows:
  1. Check the version of LMTools through Help > About
  2. Check in the "Config Services" tab that the paths are pointing to the latest versions of lmgrd and license.dat
  3. Confirm the license.dat has the DAEMON line pointed to the latest MLM.exe
Follow these steps to check the version of FlexLM on Linux and MacOS:
  1. Navigate to usr/local/MATLAB/R20XXx/etc or /Applications/MATLAB_R20XXx/etc
  2. Run the “lmver” command
  3. Check that you are running the latest version of license manager binaries.
    1. You should also make sure you are correctly referencing the vendor daemon. Pointing to the wrong file or not specifying that the vendor daemon being used is MLM will cause this error. Remember that MLM is specified as the vendor daemon and then its file location is specified.
For instructions on updating the License Manager, please refer to the following article:

Incorrect HostID

To resolve this issue, verify that the Host ID of the license server matches the license.dat and network.lic files. For more information on Host ID, see the following Article:

Expired License

To resolve this issue, please obtain an updated license that is not expired.
Tech Support
Tech Support on 13 Apr 2018
Hi Sadhan,
If you are still having trouble editing the license.dat file, please contact MathWorks support:
MathWorks Installation & Licensing Support

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More Answers (7)

Daru Nurisma Pramukti
Daru Nurisma Pramukti on 1 Mar 2016
Cody Lamke
Cody Lamke on 15 Sep 2020
Edited: Cody Lamke on 15 Sep 2020
If you are still experiencing this issue, please contact MathWorks support:

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Bill Tubbs
Bill Tubbs on 22 Jul 2020
Edited: Bill Tubbs on 22 Jul 2020
This is far too complicated and there are too many potential solutions.
I have this error after installing MATLAB on a second computer (due to needing to take the original one in for a service). It worked fine after first install, but then I needed to run MATLAB on the original computer one more time before sending it for service and now (even after fully shutting it down and restarting the second computer) I get this error when I try to launch MATLAB on the second computer.
Some advice would be appreciated. E.g. which of the 5 possible causes is most likely given my situation decribed above?
My setup: Mac OS X 10.13.6 with MATLAB 2019b on a Université Laval license using Cisco AnyConnect VPN
Diagnostic Information:
Feature: MATLAB
License path: /Users/billtubbs/Library/Application Support/MathWorks/MATLAB/R2019b_licenses:/Applications/MATLAB_R2019b.app/licenses/license.dat:/Applications/MATLAB_R2019b.app/licenses/network.lic
Licensing error: -97,121.

Orion Poplawski
Orion Poplawski on 12 Mar 2014
You might have a conflict with a different product that uses the license manager. Make sure that LM_LICENSE_FILE does not point to the file of a different product.

tom.nieth on 18 Aug 2016
I installed Matlab 2016a on a Windwos Server 2012. When I start the client I get the above mentioned error message. Why the matlab client can cause a license server error message? Someelse ran into that too?
Other clients based on Windows 7 connecting well to license server machine. Which should proof license server is up and running and firewalling shoud be ok on server side.
I opened firewall completly on the troubled client with no effect. error persisting. I checked license server firewall log to see any client request coming in. no incoming requests.
To me it seems the matlab 2016a client thinking himself to be a license server instead an application or something like that.
Many thanks in advance. Tom

Caio Santos
Caio Santos on 11 Aug 2020
As Bill Tubbs quite rigthly said, this is far too complicated and there are too many potential solutions.
I was using MATLAB R2015a without any problems until as recently as this morning, when I started to get this message:
Licence checkout failed
Licence Manager Error -97
Licence Manager cannot start
Check that the specified ports in the license file are not already in use
Restarting your machine may clear the ports.
Trobleshoot this isseu by selecting the button celow or visiting:
Diagnostic information:
Feature> MATLAB
Licence path C:\Users\user\AppData\Roaming\MathWorks\MATLAB\R2015a_licences\*.lic;C:\Program Files\MATLAB\R2015a\licences\licence.dat;C\Program Files\MATLAB\R2015a\licences\network.lic
Licensing error: -97, 121
Restaring did not help, and, sometimes, instead of this message, I get error -15.
I am using MATLAB R2015a on a windows10 computer. I am on a University of São Paulo license using Cisco AnyConnect VPN
Any idea on which problem is more likely ? Anything more specific than the answer at the top would be very appreciated.
  1 Comment
Colin Fraser
Colin Fraser on 19 Aug 2020
If you are still experiencing this issue, please create a service request below.
-Colin Fraser

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Shivam Khurana
Shivam Khurana on 7 Mar 2022
you recieve license questions because your liceense has expired. Pay money and get it or you can sign up for a 30 day trial. You can renew it for a lot of times. My university has given me matlab course but they don't own the software so even i am using the trial version

Adnan on 26 Aug 2022


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