When the MATLAB client is open, it will send a heartbeat signal to the Network License Manager every 10 minutes.
If the MATLAB client loses its connection to the Network License Manager, it will stop sending a heartbeat.
Within the next 10 minutes after the client loses its connection to the Network License Manager, the client will receive the following warning message in the MATLAB command window:
MATLAB has lost its connection to the Network License Manager.
MATLAB will make 10 more reconnection attempt(s) and then exit. Any unsaved changes will be lost.
When a user receives this warning, they should save their work and close MATLAB as soon as possible to avoid any data loss.
If the user continues to use MATLAB, they will receive the warning message every 2 minutes, for a period of 20 minutes (i.e. the message will be displayed 10 times).
After that, MATLAB will continue to stay open, but will no longer be usable.
Certain types of network disconnections may cause MATLAB to become unusable within 10 minutes of disconnecting rather than after the retry loop. For example, if the client computer disconnects from a VPN which was being used to connect to the license manager, MATLAB may hang in the "Busy" state while attempting to complete the heartbeat communication because it can no longer resolve the hostname of the server hosting the Network License Manager. This is similar to some license-related MATLAB startup issues. For more information, see:
NOTE: If this warning is displayed every time you start MATLAB and you are using a license on a redundant server, then the client installation may not be configured properly. Please see "Section 7: MATLAB Client Setup" in the following article:
