Platform: All Platforms Versions: All versions

Problem Description

I have a floating network license and get an error message dialog box  containing the phrase:
Licensed number of users already reached
I am quite sure that nobody else on the network is using the license.

The detailed error message displayed by COMSOL:

Could not obtain license for COMSOL Multiphysics GUI.
License error: -4.
Licensed number of users already reached.
Feature:     COMSOLGUI
License path: C:\Program Files\COMSOL\COMSOL53\Multiphysics\license\license.dat;
FlexNet Licensing error: -4,132. System Error: 10061 ""


If you are a classkit license (CKL) user, please refer to Knowledge Base 1078.

First of all, make sure that you are really not over-drafting the number of users in the license pool. When you have ascertained that the number of concurrent users do not exceed the number you have licensed, go on with the troubleshooting guide below.

Linux specific solutions

If you want to run several COMSOL Desktops beside each other on a Linux system (same user, same host), you have to use the same terminal window for all desktops, in order not to check out a new license for the second COMSOL process. You can do that by adding "&" at the end of the comsol start command, in order to get back the prompt after the first comsol command:
comsol &
comsol & will start two COMSOL desktops and only use one license.  If you on the other hand use different terminal windows for each command, each terminal will check out a new license seat.

LiveLink for MATLAB on Linux

If you are licensed the COMSOL LiveLink for MATLAB, and try to start COMSOL with MATLAB, and also start a COMSOL Desktop, use the following command to start the COMSOL with MATLAB process: comsol mphserver matlab -mlroot MATLAB_path &
This will give you back the command prompt in order to start a new COMSOL Desktop, from the same terminal window as before.

General solution

The following procedures are meant to be addressed only by a qualified license administrator. If you are not, please contact your system administrator.

The problem of licenses not being returned to the license manager may be due to:

  1. A COMSOL process is still running on the client computer. Please check if there are any (crashed) "comsol.exe", "comsol", "java.exe"  or "java" processes still running on the computer. Close/kill any such processes, see if the license key is returned to the license manager.
  2. A graphics driver issue. Some users have reported that updating the graphics driver solved the problem. The latest graphics drivers for most graphics cards are available at or On the Windows platform, it may help to switch from OpenGL to DirectX rendering. The rendering settings are available on the menu Options/Preferences/Visualization.