Why do I receive License Manager Error -4?

When I try to start MATLAB or use a toolbox, I receive the following error:

ERROR: License Manager Error -4
Maximum number of users for MATLAB reached. Try again later

What does this error mean and how can I resolve it?

Answer 1

[MathWorks Support Team]

This error indicates that all licenses are currently in use. This means that all of the keys for a particular product have been checked out from your license server. You will not be able to access a license for the product until another user has returned the license back to the pool. For information about the current licenses in use you can check with your License Administrator. Your License Administrator can check the usage of licenses by following the instructions in the License Administrator Section below.

This error can also occur if there is a misunderstanding as to what products are owned. For example, if the Network License Manager has a 2 licenses for MATLAB R2022b and 3 seats for MATLAB R2021a, then 5 seats could check out R2021a and older, but only 2 seats could check out R2022b. Trying to checkout a third seat would result in an error -4.

License Administrator Section

Windows:

1) Launch LMTOOLS, located within the $MATLAB\etc\win64. If lmtools.exe is not in that folder, see the related solution "Why are necessary license manager scripts missing from my license manager directory?" below.

2) Click the "Perform Status Enquiry" button on the SERVER STATUS tab to get a full report of the current license usage.

For Linux/Mac:

1) Open a terminal Window. For Mac OS X, use the Terminal application located in the Applications/Utilities directory.

2) In the terminal, change directories to the $MATLAB/etc directory. For example:

Linux

cd /usr/local/MATLAB_R2022a/etc

Mac OS X

cd /Applications/MATLAB_R2022a.app/etc 

3) Run the following command to get the usage information

./lmstat -a -c license.dat

An example output from LMTOOLS or lmstat is located below:

--------
Status
--------
Flexible License Manager status on Mon 9/26/2022 15:35
[Detecting lmgrd processes...]
License server status: 27000@license1
    License file(s) on license1: C:\Program Files\MATLAB\R2022b\flexlm\license.dat:
 license1: license server UP (MASTER) v11.18.1.0
Vendor daemon status (on license1):
       MLM: UP v11.18.1.0
Feature usage info:
Users of MATLAB:  (Total of 2 licenses issued;  Total of 2 licenses in use)
 "MATLAB" v22, vendor: MLM
  nodelocked license, locked to "ID=123456"
    joesmith joe-pc joe-pc (v22) (joe-pc/27000 102), start Mon 9/28 15:37
    janedoe jane-pc jane-pc (v22) (jane-pc/27000 101) start Tues 9/29 08:26

In this example, a license would not be available until either Joe or Jane closes MATLAB to return the license.

[Jerry Fausz]

But why do I get this error even when 'lmstat' indicates there are many licenses available?

[Shawn Lyons]

@Jerry Fausz

It is possible that your MATLAB is reaching out to a different server than what you are entering into the lmstat command, if there are multiple license servers at your organization. The server hostname is editable in the network.lic file inside the 'licenses' folder of your MATLAB installation. Open that file in a rich text editor, and confirm that it is listing the same server that you are contacting with the lmstat command.

If you are unable to resolve the problem, please contact MathWorks support for assistance.

https://www.mathworks.com/support/contact_us.html

-Shawn

MathWorks Support

[Deepak Rathore]

Hi I am Facing same problem when I follow the solution given above, I got the following:

Error getting status: Cannot find license file.

The license files (or license server system network addresses) attempted are

listed below. Use LM_LICENSE_FILE to use a different license file,

or contact your software provider for a license file.

Answer 2

[Loic Houde]

Hello, who can ne explain me that only 2/5 licenses are used and no more instance of matlab can be launch.

thanks,

#./lmstat -a -c license.dat

Users of MATLAB: (Total of 5 licenses issued; Total of 2 licenses in use)

"MATLAB" v34, vendor: MLM, expiry: 01-jan-0000
floating license

----------------------------------- # matlab MATLAB is selecting SOFTWARE OPENGL rendering. License checkout failed. License Manager Error -4 Maximum number of users for MATLAB reached. Try again later.

Answer 3

[Nelson Nwaogu]

why am i getting this message while i purchased a licence?

[Scott]

Hi Nelson,

Typically you'd see this error on a license shared by a company or school, not on a license you purchased individually. Please contact MathWorks support if you're seeing this error in relation to a license you've purchased.

https://www.mathworks.com/support/contact_us.html

-Scott

MathWorks Installation & Licensing Support

Answer 4

[Seyedmajid azimi]

Hi,

in my machine in the path below there is not lmstat! cd /usr/local/MATLAB_R2010b/etc

/usr/lib/matlab-8.6/etc$ ls glnxa64 LicenseAdministration.pdf

/usr/lib/matlab-8.6/etc/glnxa64$ ls lmgrd lmutil MLM

what is the problem? I'm faced with a following error which it reffered to this link.

fast_rcnn startup done License checkout failed. License Manager Error -4 Maximum number of users for Distrib_Computing_Toolbox reached. Try again later. To see a list of current users use the lmstat utility or contact your License Administrator.

Troubleshoot this issue by visiting: https://www.mathworks.com/matlabcentral/answers/101313-why-do-i-receive-license-manager-error-4

Diagnostic Information: Feature: Distrib_Computing_Toolbox License path: /home/azimi/.matlab/R2015b_licenses:/usr/lib/matlab-8.6/licenses/license.dat:/usr/lib/matlab-8.6/licenses/*.lic Licensing error: -4,132. Error using gpuDevice (line 26) The GPU functionality requires a Parallel Computing Toolbox license.

Error in auto_select_gpu (line 15) g = gpuDevice(i);

Error in script_faster_rcnn_demo (line 9) opts.gpu_id = auto_select_gpu;

[Scott Isabelle]

The same problem: no lmstat in /Applications/MATLAB_R2010b.app/etc on Mac, macOS 10.12.6

There is lmutil in /Applications/MATLAB_R2010b.app/etc/maci64

./lmutil lmstat -c <licensefile> should work, but where is license.dat stored?

[Kyle Perry]

Hello,

If you are still receiving an issue running then please contact our support team so we can help find out the cuase of the issue. I have attached a link below that contains all the information for the license manager commands and another that contains the link to our support team.

https://www.mathworks.com/help/install/administer-network-licenses.html

https://www.mathworks.com/support/contact_us.html

Answer 5

[Jennifer Dhont]

Hi,

I get the same error:

License checkout failed. License Manager Error -4 Maximum number of users for MATLAB reached. Try again later.

Troubleshoot this issue by visiting: https://www.mathworks.com/matlabcentral/answers/101313-why-do-i-receive-license-manager-error-4

Diagnostic Information: Feature: MATLAB License path: Licensing error: -4,0.

But I am using a Free Matlab Trial, got the license id when asking for a trial and I am the only user. The trial worked perfectly for a week, installed last week so 30 days are not over yet.

Can anyone help?? Thanks!

Jennifer

[Kyle Perry]

Hi Jennifer,

This usually means that you most likely have a network license file on your computer that MATLAB is detecting. Please contact us and we can help resolve the issue.

https://www.mathworks.com/support/contact_us/

Answer 6

[Paz dosa]

I get the same error. In my case lmstat -a shows: ... Users of MATLAB: (Total of 31 licenses issued; Total of 13 licenses in use) ...

Which seems to indicate that there are plenty of available licenses. The license servers used are correct. Any idea what to do next?

[Sebastian]

Were you able to find a solution to the difference on the total number of licenses issued vs licenses in use?

Answer 7

[Stefano Tirelli]

Hello, same problem: Matlab not running - licenses available. Why?

[Kwami Sedzro]

Same issue

[Sebastian]

Seeing the same issue with licenses issued vs licenses in use. Were you able to get a resolution?

Answer 8

[Freeman Tang]

Hello, I need license setup please.

Thanks,

Freeman