The following error appears in the log files on the License Server and the connection to the License Server is disconnected:
Lost connection to lmgrd, heartbeat timeout expired, exiting. EXITING DUE TO SIGNAL 28 Exit Reason 5.

To resolve the issue, disable port monitoring on the Citrix Licensing Server, or add exceptions or rules to the daemon ports, typically port 7279 to not allow port monitoring on that specific port.

Problem Cause

This issue can occur when there is a break in the communication within the 7279 daemon port of the licensing server. The break can occur because of a random port scanning on the server.

Verify the lmadmin.log file for the Licensing server in the c:\program files\citrix\licensing\ls\logs\ folder. This lmadmin.log file initially shows that there is a continued break in communication.

The c:\program files\citrix\licensing\ls\logs\CITRIX.log file gives more information about the loss of connection to the Licensing Server:

The preceding error indicates that there is a loss of connection, because the heartbeat is timing out.

In this scenario, the application event log shows a consistent entry from McLogEvent. This entry is a port monitoring software function from McAfee:

The port scanning software is interrupting the established connections to the Citrix Licensing server causing the heartbeat to the port to timeout and eventually causing the service to lockup.

Citrix eDocs - Changing Port Numbers