KB45023 - Lease licensing fails with " License server low-level protocol error, server=X.X.X.X, Code = [28] :Operation timed out'

This article provides details on the issue where the license server fails to lease licenses to the license client with the following
Message " License server low-level protocol error, server=X.X.X.X, Code = [28] :Operation timed out'.

When attempting to lease licenses to a license client, the following message will appear in the event log:
License server low-level protocol error, server =X.X.X.X, Code = [28] :Operation timed out'

Issue occurs whenever there is a connection lost or intermediate connection between PCS client and PCLS (pcls.pulseone.net).

The license server should have accessibility to the client on port 443, when there is a communication issue or intermediate connection loss it fails to fetch the license information from the server.
The license server must be able to communicate with the server (pls.pulseone.net), this can be verified by performing port probe  test to check the status of the port.
The “error code 28” is an generic error which may occur due to different parameters, in order to narrow down the issue ,collect the following set of logs to figure out the root cause and open a support case.

1.System snapshot with debug log enabled while replicating the issue.  (See below for debug log settings.)
   1.Navigate to Troubleshooting > Tools > Licensing Protocol Trace

1. Click Start Trace

2. Navigate to Troubleshooting > Monitoring > Debug Logging

• Set the Max Debug log size to 50

• Set the Debug lLog level to 10

• Enter the following Event Codes: pbLogHandler, ClientMessageHandler

Leave the above logging running long enough to replicate the issue.  Once the license client fails to lease the license from the server with the error "License server protocol error- code 28", follow the below steps to gather the logs.

2.PCS device logs:
                  To save Admin Access, User Access and event Log file:

• In the admin console, choose System > Log/Monitoring > Select Event.

• Click Save All Logs, navigate to the desired network location, enter a file name and then click Save to manually save the log file.

 3.Navigate to Troubleshooting > System Snapshot

4. At the bottom of the page, select the checkbox to Include Debug Log.

5. Click Take Snapshot to take the system snapshot and wait for the file to be generated before browsing away from the page. 

6. Download the system snapshot from the device. 

7. Navigate to Troubleshooting > Monitoring > Debug Logging and disable debug logging and Save Changes. 

8. Navigate to Log / Monitoring > Event Log.

9. Click to Save All Logs.

10. Attach the System Snapshot and device logs to the case.